Interesting thing is that also Bible tells God is greater than Jesus:
the Father is greater than I.
John 14:28
If Jesus says the Father is greater than him, is there some reason not to believe Jesus?
Same thing comes also from the teachings of Paul:
For, "He put all things in subjection under his feet." But when he says, "All things are put in subjection," it is evident that he is excepted who subjected all things to him. When all things have been subjected to him, then the Son will also himself be subjected to him who subjected all things to him, that God may be all in all.
1 Cor. 15:27-28
I think it is sad, if people call themselves Christian (disciples of Jesus), when they don’t really believe what Jesus says.
Bible also tells Jesus is the image of God, which I think should be believed, if one is truly a disciple of Jesus.
…in whom we have our redemption, the forgiveness of our sins; who is the image of the invisible God, the firstborn of all creation…
Colossians 1:14
I think the simplest way is to believe Jesus and follow him, if one wants to be a real disciple of Jesus (“Christian”).