Anyone can say they are God, but Jesus did more than claim to be God, He backed up His claims. He proved that He was the Son of God (equal with God, John 5:18) by:
1. Fulfilling hundreds of Old Testament prophecies
2. Performing numerous miracles
3. Living a sinless life
3. Resurrecting from the dead
It's one thing to make grandiose claims, it's another thing to back them up.