And Jesus said unto him, Why callest thou me good There is none good but one, that is, God. (Mark 10:18; cf. vv.17-22; Matt 19:16-22; Luke 18:18-23)
This verse is often used by many to deny the divinity of Jesus, and instead, argue that the New Testament affirms a Socinian or some other form of (very) low Christology.
For instance, Anthony Buzzard and Charles Hunting, as if it was a matter of fact, wrote:
Jesus is reported as saying he was not God (Mark 10:18). (The Doctrine of the Trinity: Christianity’s Self-Inflicted Wound, 333)
In another book, Buzzard argues that Mark 10:18 is support for his Socinian Christology:
When a young man addressed Jesus as “good teacher,” he immediately challenged this greeting by pointing out that “one only is good, the one God” (Mark 10:17-18).
In none of his recorded sayings did Jesus state, “I am God.” If he had said this, he would have been heard to say, “I am the Father,” since he constantly referred to God as his Father. (Jesus was not a Trinitarian: A Call to Return to the Creed of Jesus, 75-76)
However, in light of the high Christology Mark elsewhere presents (see Michael Tait, Jesus, The Divine Bridegroom, in Mark 2:18-22: Mark’s Christology Updated [Analecta Biblica 185; Rome: Gregorian and Biblical Press, 2010]), it would be unwise to absolutise this verse in Mark to preclude any high Christology in this gospel. Indeed, I would actually agree with Robert L. Reymond (1932-2013), one of the leading Reformed theologians in recent decades, who argued Mark and the other Synoptic Gospel authors are not addressing one way or another the divinity of Jesus. In his book on New Testament Christology, Reymond wrote:
But does Jesus’ response imply the contrast between Himself and God that is the core of this interpretation? The enclitic (unemphatic) με Jesus employs to refer to Himself simply will not bear the weight of this inferred contrast. Nor will its position in the sentence support the weight of this inferred contrast either, since, as Blass and Debrunner observe, “the old rule, observable in Greek and cognate languages, that unemphatic (enclitic) pronouns and the like are placed as near the beginning of the sentence as possible . . . applies also to the NT” (F. Blass and A. Debrunner, A Greek Grammar of the New Testament and Other Early Christian Literature, translation of 9th-10th German edition [Chicago: University of Chicago Press, 1961], p. 249, sec. 473 [1]). Moreover, such an inferred contrast “throws into chief prominence a matter which lies quite apart from the main subject under discussion” (Warfield, Person and Work of Christ, p. 161), that is, the contrast not between God and Jesus, but (as Matthews account brings out clearly by reporting Jesus’s question, “Why do you ask Me about what is good?”) between God as the only true standard of goodness and any and all others who prescribe other standards for acquiring eternal life. Jesus’ implied point is that, as a Jew, the man already had God’s revelation on the matter. Warfield explains:
The whole emphasis is absorbed in the stress laid upon god’s sole right to announce the standard of goodness. The question of the relation of Jesus to this God does not emerge: there is equally no denial that He is God, and no affirmation that he is God. The young man is merely pointed to the rule which had been given by the good God as a witness to what is requisite to do that we may be well-pleasing to Him. He is merely bidden not to look elsewhere for prescriptions as to life save in God’s revealed will. The search for a master good enough to lead men to life finds its end in God and His commandments. (Person and Work of Christ, p. 158-59)
This is the contrast Jesus intended, not a contrast between Himself and God. Immediately after His opening response He declared, “You know the commandments” (Mark 10:19); “If you would enter life, keep the commandments” (Matt. 19:17).
I. Howard Marshall agrees with Warfield that Jesus intended no contrast between or comparison of Himself and God in the passage. The point He wished to make was altogether another matter:
Jesus’ answer is meant to do away with any cheapening of the idea of goodness. True goodness belongs to God, as the OT testifies . . . There is no reason to regard Jesus’ statement as a confession of sinfulness, since this would be at variance with the rest of the Synoptic tradition . . . The Christian reader may go to the other extreme and see here a tacit identification of Jesus with Go, but this lies beyond what the passage actually says. (Marshall, Gospel of Luke, p. 684)
So this saying, by which critics allege that Jesus rejected any thought of being divine, actually does not address the issue one way or the other. Neither should it be construed as a confession of sin on Jesus’ part. (Robert L. Reymond, Jesus, Divine Messiah: The New Testament Witness [Phillipsburg, N.J.: Presbyterian and Reformed, 1990], 123-24)