Divinity of Jesus

Question:
If Jesus is God, why did Jesus respond the way he did in Mark 10:18?
Answer:
The affirmation of Jesus’ deity is very clear in the Bible. Jesus did claim Himself to be divine and the New Testament writers rightly called Him God. The statement Jesus is making in Mark 10:18, "Why do you call me good?" Jesus answered. "No one is good—except God alone",
are not contradicting His divine claims.

The man (called as rich young ruler) addresses Jesus in Mark 10:17 as Good Teacher. He bends his knees before Jesus and enquires what he needs to do to inherit eternal life. While on the outset it appears he is on the right track we see from studying the passage that his intentions were not right and his priorities were misplaced. Both his assumptions were wrong – firstly he considered Jesus as a mere moral teacher, and secondly he thought salvation can be earned through good works. Jesus wanted to correct his two wrong assumptions. Jesus wanted the young man to realize His full identity. Jesus didn’t want him to merely see Him as a good teacher.

This statement of Jesus in Mark 10:18 actually is an affirmation that He is God. Jesus was making the person understand that God alone is good, and if he is calling Jesus as good then he also has to acknowledge Jesus as God. The young man however did not grasp this truth.