Jesus never says the exact words ‘I am God’ but he speaks and acts with God’s authority… In Mark 2 he forgives a man’s sins and the religious leaders object, because only God can do that.
In the trial in Mark 14, Jesus says he’ll sit at God’s right hand and come with the clouds of heaven. The people hearing him know what he’s claiming and charge him with blasphemy.
When historic Christianity calls him ‘Son of God’ it means the Father and the Son are distinct and both fully God.