Because as we are told in Chapter 1 of the book of John that Jesus became flesh when he was born. He was like Adam in that he was a new DNA (not inherited from a human Father) but a sinless DNA, the 2nd Adam as we are told but he was still flesh and blood and lived as we do in human form and died as we do in human form. He indeed was God and the Power of God was with him as he lived as a human but he never abused it. When they came for him to kill him he had the power to call and wipe his enemies out but he let them in obedience crucify him as a little lamb, blameless. He knew that was his purpose and his death as a human is what brings us eternal life. The Father and Holy Spirit were always with Him while he lived in the flesh. In 2 Peter read what Peter wrote as an eyewitness. He saw Jesus do many incredible things that Jesus did by prayer and faith in the flesh. Jesus told his disciples they could do the same if they prayed and they did many incredible things like bringing people back from the dead but they were not God they just had faith like Jesus did when he was in the flesh human form. Many things remain a mystery but God has revealed a lot and what he has revealed we can comprehend. There is so much more that we as limited human minds could never understand even if he told us about it. That is why the bible says the entire world could be filled with books about Jesus and what he did. Logic on this is simple, God in 3 persons Father, Jesus, and Holy Spirit. Jesus perfectly in human form reflected the Father. Jesus said if you have seen me you have seen the Father. The Holy Spirit perfectly reflects Jesus. One real life experience for me was when 2 boys saw Jesus as I was praying for a boy who was a minute or two from death. Jesus in the form of the Holy Spirit came into the cabin light up through the wall. Stopped, smiled as he stood between 2 boys, and walked over to the boy who dying, touched him and disappeared. I told the boys it was an angel later after the dying boy immediately came to life again. The boys who were 10 and 11 said no it was Jesus. I asked them how they knew and they said we saw his hands. His hands had holes in them and were scabby not bloody. Now how could a 10 year old boy dream that up. They also described his crown which was amazing. One of those boys is now a principle at a large Indiana high school. Occasionally I speak with him about this. He says he thinks about seeing Jesus every single day. It changed his life. But it was not physical Jesus it was the Holy Spirit who perfectly reflected Jesus. They are one. The entire nature and function of God is beyond logic. It is not logical for a virgin birth, walking on water, feeding 5000 men with a few scraps of food, changing water into fine wine. But then again creating every life form with a complex DNA code and other codes we are just discovering is also difficult. He created everything from nothing. And he will again recreate us with new bodies, improved coding that will last forever and will create a new heaven and new earth a paradise for those who believe in Jesus to live with him forever. And it will not take millions of years in the new creation it will be very quick. Those Christians who try to compromise with evolution are fools. They forget to be a Christian is to be a Supernaturalist. If one is not a supernaturalist one cannot be a strong mature Christiian.