Jesus is indeed the God in the flesh. The Bible confirms this over and over again. Most Christians point to John 1:1 which is great, but there are many other scriptures as well which point to this fact. The fact that Jesus Himself claimed to be the Son of God, which, to the Jews of the time was Blaspheme since a son in the Jewish culture is equal to the father. This was the reason that they used to crucify Him.
Jesus' death is portrayed as a tragedy by many, although the fact is, that it was necessary. It was a gift to all mankind. God in the flesh took the punishment for sinful mankind. It could only be a perfect sinless Human sacrifice. Therefore, no other human being could serve as this sacrifice because we all fall short of God's Holiness, we mess up (sin).
Only God becoming a man would work. He took the form of a man and He died so that mankind could be forgiven. It was His gift of Grace. Jesus himself said, I and the Father are One. He also called Himself "I am" which is the name of God, given to Moses on Mt Sinai prior to leading the Hebrews out of Egypt. This almost got Him stoned, but His time had not yet come so he was able to disappear into the crowd. Some cult religions who call themselves Christians don't believe He was God and actually believe he was an Angel. the problem with that is that Angels worship Him. Secondly, an Angel is not human and could never take the punishment for a Human. Sin entered the world through man and had to be conquered by a man.
So was Jesus just a man? No. Jesus was a man, but He was also God in the flesh. How much more loving can God be than to sacrifice Himself for those He loves. God is Holy and man can not stand before a Holy God, fin a body of sin. We must be righteous and perfect before God. Since we weren't, He became sin for us. He exchanged His righteousness for our sin. Hal Lindsey gives a perfect Acronym for GRACE: God's Righteousness At Christ's Expense.
Hope this helps. God Bless.