Jehovah’s Witnesses often quote John 14:28 in trying to show their view that Jesus is less than Almighty God. In the verse, Jesus says “The Father is greater than I.” To the Jehovah’s Witnesses, this means that Jesus is less than the Father, and therefore of a different nature than the Father, and Jesus is not God.
First, the distinction that the JW’s make between Almighty God and God is a distinction without a difference. If God is God, then He is Almighty. There is no sort of mighty god or any true god of any sort that is not the one true God. If there is a god that is not the true God, then it is a false god. There is Jehovah God, and all other gods are false gods. The Bible leaves us no room for a good God other than Jehovah God.
Second, the verse in John 14:28 merely means greater in position, but does not mean greater in being or nature. Just as the President of the United States is greater in terms of his position, he is still a human being, and in terms of his humanity is equally great as any other human. As the Son who voluntarily took a human nature, Jesus as Son can say that the Father is greater in position. Jesus as Son is still equally God as much as the Father and the Holy Spirit.
The teaching of the Jehovah’s Witnesses is the same Arian heresy that was removed from the church at the council of Nicea in 325. As such, it is outside of Christianity.