17 And when he was gone forth into the way, there came one running, and kneeled to him, and asked him, Good Master, what shall I do that I may inherit eternal life?
18 And Jesus said unto him, Why callest thou me good? there is none good but one, that is, God. (Mark 10)
Why would Christ say that "there is none good but one, that is God"?
Note that the word Good in verse 17 is CAPITALIZED. Hence, the man who came running to Christ was using the word as a noun rather than as an adjective. As a noun, the Greek word for Good is agathos' which means "intrinsically good and is often used as a noun." A person who is intrinsically Good is One who, by His very nature, has the characteristic of good belonging to Him. Hence, since the man used the word as a noun, it was appropriate for Christ to refer to His Father as the only One who is Good, for even Christ obtained "grace for grace" from His Father (see D&C 93:12-14; compare D&C 50:26-27). Christ was simply pointing this out and reminding the man that God, the Father, "should be the only being whom [we] should worship" (see D&C 20:19).
If the man had used the Greek word kalos' instead, it would have been recorded "good Master" by the disciple Mark. Kalos' means "beautiful, morally good, better, fair, honest, or worthy." In that case, the Savior would have made no correcting comment for, indeed, Jesus Christ is these things.
It is instructive to note that the man dropped his usage of Good and afterwards referred to Jesus Christ as "Master" (see Mark 10:20)
