[Ali Imran]

This is not a denial of his divinity.... but a challenge to the young man, prompting him to consider the true meaning of "good" and to recognize that only God possesses ultimate goodness. 

It is not a quality that can be earned through human works but is a divine attribute.

It is rather moot to discuss this because, at the end of the day, we do not know which book is giving us the actual answer from Jesus.