CLAIM: Jesus says, “Why do you call Me good? No one is good except God alone” (Lk. 18:19). Cultists and skeptics argue that Jesus is claiming that he is not God in this passage. Is this the case?
RESPONSE: The context for this passage is self-righteousness: the rich young ruler believes that he is as righteous as God and deserves eternal life (v.21). Jesus is calling this man’s view of righteousness into question. When the man calls him “good,” Jesus is basically asking the question, “Do you realize what ‘good’ really is? It’s based on the holy and perfect character of God!” In other words, Jesus was admonishing this man for throwing around the term “good” in such a cavalier way. Leon Morris writes,
His greeting, Good Teacher, was not in use among the rabbis because it ascribed to man an attribute possessed only by God (according to Plummer there is not one example in the whole Talmud of a rabbi being addressed in this way; Fitzmyer finds one example, but it is dated in the fourth century.
Jesus was not denying that he was God here; instead, he was calling this man’s view of goodness into question. Furthermore, we can turn this argument on its head:
(1) Jesus was perfectly good.
(2) Only God is good.
(3) Therefore, Jesus is God.
It’s interesting that cultists regularly affirm the impeccability of Christ (Premise 1). So Jesus’ deity would follow from their own admission. Of course, elsewhere, Jesus’ deity is regularly affirmed by him (see “Defending the Deity of Christ”).
 Morris, L. (1988). Luke: an introduction and commentary (Vol. 3, p. 284). Downers Grove, IL: InterVarsity Press.