Christians love to talk about theology. There is an uncountable number of books, blog posts, and podcasts that are made just for you to learn theology. But they often fail to give you the biblical foundation you need before you dig into more complicated topics.
What should Christians believe? Christians believe in the gospel of Jesus Christ: the sinfulness of mankind, the incarnation, atonement, and resurrection. They believe in the inerrancy and authority of the Bible. And they believe in the holiness, love, and power of the Triune God.
As time goes on, Christians should mature in their understanding of who God is. That is the meaning of theology.
Hebrews 4:11-14 establishes that some Christians need milk and not solid food. Meaning that you have to get the basics down before you try moving on to more weighty topics.
The goal is to be mature enough to eat solid food. In this article, I want to go over the basics of Christian theology so that you can have what you need to move on to more advanced study.
I’ll also include a list of some common theological vocabulary you might need to know.
The Gospel of Jesus Christ
The gospel of Jesus Christ is the foundation for Christian theology.
When delivering the gospel, the apostle Paul writes:
For I passed on to you as most important what I also received: that Christ died for our sins according to the Scriptures, that he was buried, that he was raised on the third day according to the Scriptures.1 Corinthians 15:3-4
While the gospel is foundational, it is also something that no Christian ever grows out of. The gospel should be your hope in every moment of every day.
So what is the gospel?
The Sinfulness of Mankind
The fundamental problem addressed by the gospel is the sinfulness of mankind.
The first man created by God, Adam, sinned by disobeying God.
As God had warned would happen, this plunged creation into a curse of sin.
Romans 5:12 says it this way: “Therefore, just as sin entered the world through one man, and death through sin, in this way death spread to all people, because all sinned.”
All of humanity stands before God as guilty.
There is no one righteous, not even one. There is no one who understands; there is no one who seeks God. All have turned away; all alike have become worthless. There is no one who does what is good, not even one.Romans 3:10-12
We are inclined to disobey God.
Our propensity isn’t toward good works and righteousness, it is toward disobedience and unrighteousness.
Theologians usually call this total depravity.
God became man. This is the essence of the incarnation.
The word refers to the “becoming of flesh”. And it biblically refers to Jesus Christ, who is God, taking on humanity.
This is summarized in John 1:14: “The Word became flesh.”
Jesus is truly and fully human. He is not half human. He does not just look like a human. He is fully man.
Jesus is also truly and fully God. He is not half God. He did not lose the fullness of his deity. He is fully God.
Colossians 2:9 says it this way: “the entire fullness of God’s nature dwells bodily in Christ.”
The Life of Jesus
Jesus humbled himself by becoming man. And he lived on earth among men.
He was born through the miracle of the virgin birth to his mother Mary.
He lived and taught in 1st century Israel.
But most importantly: he lived a perfect and sinless life.
While we all fall short of the glory of God, Jesus did not. He did not deserve the wrath of God.
Unlike us, he did not deserve to be separated from God.
His earthly life and teachings are recorded in the four gospels: Matthew, Mark, Luke, and John.
He performed miracles, preached sermons, and ultimately died in our place.
Jesus was crucified for our sins.
Jesus died in our place, taking our punishment, and removing the wrath of God for our sins.
Theologians sometimes refer to this as the penal substitutionary atonement.
God is just and does not allow wickedness and evil to go without consequence.
In fact, God hates sin. He despises wickedness and evil. And it is right for him to do so.
Jesus died as a sacrifice on our behalf.
He removed the wrath of God. This is sometimes called propitiation.
But he was pierced because of our rebellion, crushed because of our iniquities; punishment for our peace was on him, and we are healed by his wounds. We all went astray like sheep; we all have turned to our own way; and the Lord has punished him for the iniquity of us all.Isaiah 53:5-6
To put it another way, 2 Corinthians 5:21 says that “He made the one who did not know sin to be sin for us, so that in him we might become the righteousness of God.”
Jesus rose from the dead.
The Bible foretold that Jesus would be raised from the dead on the third day.
In fact, even Jesus foretold this about himself.
Jesus answered, “Destroy this temple, and I will raise it up in three days.” … But he was speaking about the temple of his body. So when he was raised from the dead, his disciples remembered that he had said this, and they believed the Scripture and the statement Jesus had made.John 2:19-22
Jesus bodily, physically, literally rose from the dead on the third day.
This is one of the most fundamental doctrines of the Christian faith.
1 Corinthians 15:14 says, “If Christ has not been raised, then our proclamation is in vain, and so is your faith.”
Jesus appeared to over 500 people after his resurrection and the apostles carried their witness of the resurrected Christ until their martyrdom.
The Great Commission
The Great Commission refers to the words of Jesus before he ascended.
All authority has been given to me in heaven and on earth. Go, therefore, and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe everything I have commanded you. And remember, I am with you always, to the end of the age.Matthew 28:18-20
There are two important statements worth memorizing here.
First, Jesus commands us to make disciples. A disciple is a follower of Christ.
This means proclaiming the gospel and teaching people to obey the Lord.
Second, Jesus promised to be with us.
This is one of the most comforting promises in all of the Bible. Jesus will never leave us. And he is always with us.
The Doctrine of the Bible
The Bible is the word of God.
It is inspired by God, meaning that they were the words of God. It was written by apostles and prophets used by God to compose the Bible.
The Bible contains 66 books and is divided into two testaments. There are 39 books of the Old Testament and 27 books of the New Testament.
The greatest discipline every Christian should be always developing is to read and understand the Bible.
The Inerrancy of the Bible
Inerrancy simply means that the Bible does not contain any errors.
Everything it says is true. The Bible is completely trustworthy because it is given by a perfect, all-knowing God who cannot lie.
The Bible is not only free of errors, it also cannot make errors.
I know this is a nuance, but it is important to know and believe that the Bible is both inerrant and infallible.
To be infallible means that the Bible can not make errors.
The Sufficiency of the Bible
The Bible is all we need to be able to know God, to understand humanity, and to live a godly life of faith.
The sufficiency of the Bible does not mean that the Bible contains every answer to every question.
The Bible won’t tell you how to change your tire, for example.
But the Bible tells us everything we need to know about God.
The Bible is a gift from God that God intended to be complete. God didn’t intend that the Bible would lack necessary information.
All Scripture is inspired by God… so that the man of God may be complete, equipped for every good work.2 Timothy 3:16-17
Scripture is able to make us complete in our faith and equip us to live a life of godliness.
The Authority of the Bible
God wrote the Bible and he is the Lord.
The Bible is not just advice. It is authoritative. It has power.
When you received the word of God that you heard from us, you welcomed it not as a human message, but as it truly is, the word of God, which also works effectively in you who believe.1 Thessalonians 2:13
Jesus Christ is Lord. Every tongue will confess this. Every knee will bow to him.
His word is not to be taken lazily. Hebrews 5:11 tells us the folly of “being too lazy to understand“.
The commands of the Bible should be obeyed. The truth of the Bible should be revered. And the Author of the Bible should be worshiped.
The Accessibility of the Bible
The great reformer Martin Luther commented that, “the Holy Spirit is the plainest writer and speaker in heaven and earth.”
The books of the Bible contains many different types of literature. From epistles and narratives to prophecy and apocalypse.
But that doesn’t mean the Bible is hard to understand.
And we have the Holy Spirit to illuminate and apply his word.
It might take study. It might mean looking into the text. But the Bible is easily understood.
The Bible is not written to be tricky. It’s not meant to be complicated.
It is meant to be written so that all people everywhere have a testament of God and the gospel.
The Doctrine of God
The New City Catechism asks the question “What is God?” Their answer is this:
God is the creator and sustainer of everyone and everything. He is eternal, infinite, and unchangeable in his power and perfection, goodness and glory, wisdom, justice, and truth. Nothing happens except through him and by his will.
The theologian A.W. Tozer said, “What comes into our minds when we think about God is the most important thing about us.”
The study of the attributes of God is often called theology proper.
I’ll go over what I believe are some of the most foundational characteristics of God.
The Holiness of God
The only attribute of God mentioned three times in a row is his holiness.
Holy, holy, holy,Revelation 4:8
Lord God, the Almighty,
who was, who is, and who is to come
This is sung by angels surrounding the throne of God day and night.
The holiness of God means that he is completely perfect.
He is perfect in his actions, his intentions, his character, his wisdom, and all of his attributes.
It means that he is other than us. His perfection is above any other perfection.
His goodness are beyond the human capacity for goodness.
His love and power are infinitely beyond our greatest ideas of them.
God is holy.
The Love of God
God is infinite in his love.
The one who does not love does not know God, because God is love.1 John 4:8
God’s love is his goodness being acted out on his creatures.
It is his benevolence and care in action.
It is the love of God that he died for us, cares for us, and makes us holy.
It is the love of God that undeserving sinners wake up every day and have the opportunity to repent.
God’s love is an extension of his goodness and kindness.
The Power of God
God has all authority over his creation.
He has all power to do whatever he chooses.
Our God is in heaven and does whatever he pleases.Psalm 115:3
There is nothing outside of the control of God. There is nothing that surprises him.
There is nothing that has ever happened that has frustrated the plan of God.
The complete power and authority of God over all things is usually referred to as his sovereignty.
God is Trinity.
God is three persons: the Father, the Son, and the Holy Spirit.
God is one being with one nature and one substance. The Father, Son, and Holy Spirit are equal in power and glory.
The idea of the Trinity might seem a little confusing at first, but it is a very foundational idea.
It impacts every other area of theology.
The Athanasian Creed was written in the first few hundred years of the church and is one of the oldest standards for understanding the Trinity. It says this:
We worship one God in trinity and the trinity in unity, neither blending their persons nor dividing their essence. For the person of the Father is a distinct person, the person of the Son is another, and that of the Holy Spirit still another. But the divinity of the Father, Son, and Holy Spirit is one, their glory equal, their majesty coeternal.
God is not three parts. He is not three gods.
God is also not one person who manifests in three different ways.
If this seems confusing now, you’ll more easily understand it as you continue to study.
Resources for Beginners
If you’re looking for books to help you jump-start your theological journey, we’ve created this video just for you.
Holiness – the holiness of God means that he is completely other than us and is perfect in his actions, his intentions, his character, his wisdom, and all of his attributes.
Incarnation – the incarnation is that the Son of God became man and took on flesh
Inerrancy – inerrancy means that the Bible does not contain any errors or imperfections.
Infallibility – infallibility means that the Bible is not able to make errors because it is the word of the perfect God.
Passion – the passion refers to the death of Jesus Christ on the cross as the atonement for our sins.
Penal Substitutionary Atonement – this is the doctrine that Jesus died in our place, taking our punishment, and removing the wrath of God for our sins.
Propitiation –propitiation is the removal of the wrath of God through the sacrifice of Jesus.
Sin – sin is disobedience to God or his law, it is wickedness or evil.
Sovereignty – sovereignty is the complete power and authority of God over all things.
Theology Proper – theology proper is the study of the attributes of God
Total Depravity – total depravity refers to the completely fallen nature of humanity in which we are inclined toward evil and unrighteousness.
Trinity – Trinity refers to the triune nature of God as three divine persons with one essence, nature, and being.
Teaching complex doctrines without laying the proper foundation leads to deep theological issues and confusion.
We have to understand the gospel, our justification and redemption.
We have to know the Bible is our only authority.
And we have to know who God is and how to worship him.
When we have the right foundation, we can mature and move on to solid food.
While we never outgrow or become too mature for the foundational doctrines, we cannot grow without their foundation.
Pastoral Resident, Cornerstone Community Church