Yes, Jesus is God, but the answer needs to be expounded upon. When we say that Jesus is God we're using the term "God" in reference to the divine nature. But we have to be careful because we don't want to say Jesus is God and fail to understand that God is a Trinity. The Christian doctrine of the Trinity is that God exists as three distinct persons: the Father, the Son, and the Holy Spirit.
So, we have to be careful when we ask if Jesus is God because we have to be clear in the answer. If God is a Trinity and we say Jesus is God, then we are saying that Jesus is a Trinity. But that is not true. So in one sense, the term "God" can be used to designate the totality of God as a Trinity, and in another sense, it deals with the divine nature.
The correct answer is that Jesus is both divine and human. In other words, he is both God and man. God has a divine nature, and Jesus possesses the divine nature as well as the human nature. This dual nature characteristic is called the hypostatic union.
We know that Jesus is God in flesh because the Bible says many things declaring this. For example,
- John 1:1, "in the beginning was the Word and the Word was with God and the Word was God.
- John 1:14, "and the Word became flesh and dwelt among us..."
- John 8:24, "unless you believe that I am, you will die in your sins."
- John 8:58, "before Abraham was, I am."
- Exodus 3:14, "God said to Moses, “I AM WHO I AM”; and He said, “Thus you shall say to the sons of Israel, ‘I AM has sent me to you.’”
- Col. 2:9, "for in him dwells all the fullness of deity in bodily form."
- Heb. 1:8, "But of the Son he [The Father] says, 'Your throne, O God, is forever and ever.'"
After Jesus died on the cross and rose from the dead, Thomas, one of the disciples, doubted that he had risen. Jesus appears to him, and Thomas responds by saying to Jesus "my Lord and my God," (John 20:28). Jesus makes no correction to Thomas about this. Titus 2:13 tells us to wait for the coming of "our great God and Savior, Christ Jesus." In John 5:18 it says that Jesus "was calling God His own Father, making Himself equal with God."
It is clear from the Scriptures that Jesus is considered to be God in flesh; that is, he is considered to be divine. The reason is that without Jesus being both God and man, he could not make a sacrifice of sufficient value to please God the Father. If he were not a man, he would not be able to die for the sins of mankind.