Christianity is much more than getting your doctrine right.
But it is not less.
You can have right doctrine and not be a Christian. You can know all sorts of true things about Jesus and not be saved. The Devil is not unaware of who Jesus really is. The first beings in the Gospels to recognize the true identify of Christ are the demons. You can know true things and not be a Christian.
But you cannot be a Christian without knowing true things.
Some doctrines are absolutely essential. You can know some truths and still be lost, but there are some truths, without which, you will not be found. What we believe about Jesus is one of those truths.
Let what you heard from the beginning abide in you. If what you heard from the beginning abides in you, then you too will abide in the Son and in the Father. And this is the promise that he made to us—eternal life. (1 John 2:24-25)
If you are interested in abiding with Jesus and abiding with the Father, you will care about the truth abiding in you. We will not know God unless we know the truth. Which is another way of saying: You do not get to heaven without theology. The promise of 1 John is that if the truth abides in you, you abide in God and you will receive what is promised to you: namely, eternal life.
So if you care about eternity–if you care about your friends, your children, your parents who do not know Jesus–you will care to tell them and to plead with them about Christ. Because if they do not know the Son–no matter how “spiritual” they are and non matter how nice they are and no matter how many positive things they say about God, all the good things they say about God or how nice they are–they do not know the Father.
Let us not send people into the world with merely a vague notion that Jesus saves without teaching them particulars about the Jesus who does save. Jesus is a Savior for every kind of person, but not every kind of Jesus saves.
Do you know Jesus Christ? Do you know this man, this God-Man, this Son, this Savior, this King, this Christ? Will you get to know this Jesus and never budge from him—the one we find in the word, the one abiding in you by the Holy Spirit, the one you received when you became a Christian? It is not an exaggeration to say that heaven hangs in the balance. Your eternal happiness depends upon it.