Everyone knows that Jesus is God, when we look at His life, some things we see don't seem to make sense. Why did He pray? Why did He say "the Father is greater than I"? Why did He say not even He knows when he will return? And indeed, how could God possibly die?
All of these things are immediately answered when you understand the Incarnation. Jesus, though being God Himself, had humbled Himself to become human. This had to happen, according to Hebrews 2:17. “Therefore, in all things He had to be made like His brethren, that He might be a merciful and faithful High Priest in things pertaining to God, to make propitiation for the sins of the people." (Emphasis added).
Notice it says "in all things". Not just some things. He couldn't simply look like a man, but retain His full Godliness. This involves a number of things, including becoming subject to the same powers man is. Scripture says Christ became "obedient to death" (Philippians 2:8), just as we are, in a sense, obedient to death.
The word "became", and similar phrases like "be made like", are particularly significant. Prior to the Incarnation, Jesus enjoyed a very different existence. Not only was He not obedient to death, but He also had a level of glory which He laid aside for purposes of His mission. This answers the whole "Father is greater than I" thing. He's not saying "I'm not God, He is". After all, Jesus even said if you've seen Him, you've seen the Father (John 14:9). The full quote, which is basically always ignored by anti-Trinitarians, is "If you loved Me, you would rejoice because I said, ‘I am going to the Father,’ for My Father is greater than I." So, what He's actually saying is "that glory I laid aside so I could come and die for you? I'm getting that back, and if you love me, that will make you happy for me".
It even explains why Jesus still prayed to the Father. Of course, being multi-personal, the Trinity enjoys perfect fellowship of Himself. The Father, Son, and Holy Spirit, is one God, yet three persons, all of whom have a perfect relationship with Himself. When the Son became a man, and was made like His brethren in all things, He did not become an atheist. He retained His communion with God.
But He did lay aside things like His infinite knowledge. This is often explained as God just "closing His eyes". When we close our eyes, we can't see even what's in front of us. But then we peek, and suddenly we see whatever we're looking at. This is why Jesus can know so much ("peeking" at His divine knowledge), while also "closing His eyes" to the day and hour of His return, leaving that knowledge to the Father.
None of this means that Jesus was somehow less God when He came to Earth. It is theologically wrong to say that Jesus could err, for example. Indeed, we get this from the mouth of the Father, whose voice manifested saying "This is My beloved Son, in whom I am well pleased. Hear Him!" (Matthew 17:5). If Christ could err, this would be foolish advice, but as it comes from the Father, we can be sure that it would be foolish not to listen to Christ.
All of this is why, to the untrained student of Scripture, Jesus seemed less Godly during His ministry than He actually is. He simply put aside many of His divine attributes for His task here on Earth. And as sovereign of all creation, this is quite within both His power, and His right. What we can be grateful for is that while no one takes Christ's life from Him, as, being God, He has the power to lay it down and take it up again (John 10:18), Jesus did indeed lay it down. For us.