Here we have the case of a man living at the time of Christ’s earthly ministry wanting to figure out what he had to do in order to have eternal life. There is no discussion in this passage of the man believing on the Lord Jesus Christ in order to be saved (Acts 16:31) because there had been no death, burial, and resurrection of Jesus yet. So, we are dealing with salvation in the transition period of Christ’s earthly ministry between the Old Testament and the New Testament.

16 – “Good” = God is good – Ps 107:1; but we are not (Rom 3:12) there is none that doeth good – in other words, Jesus was saying, “if I’m good then I must be God, but if you don’t believe I’m God why are you calling me good?”

16 – “What good thing” – Jesus hadn’t died on the cross yet, so men were still in the Old Testament mode of doing righteousness and good works to be saved; yet Jesus was here so he was trying to get them to “follow” him.
17 – “Keep the commandments” – Jesus’ answer reveals that this is not New Testament salvation. The Old Testament called for men to keep the commandments to be saved (Deut 8:1; Gal 3:12). According to Gal 3:10, the trouble with keeping the commandments is that a man is under a curse if he doesn’t keep them all; so Christ came to redeem us from that curse (Gal 3:13). During Jesus’ ministry, as now, the law should have directed its adherents to Christ (Gal 3:24). It should have shown him that righteousness is in Jesus Christ (Rom 10:1-4) [or in the case of the rich man, in “following” Jesus, since Christ hadn’t died yet].
18 – “Which?” – That’s a strange question, like Lk 10:29; the man was trying to justify himself.

18-19 – Jesus mentioned these commandments – 6th (Ex 20:13), 7th (Ex 20:14), 8th (Ex 20:15), 9th (Ex 20:16), 5th (Ex 20:12), and 2nd (Matt 22:39; Lev19:18).

Jesus left out the 1st (Ex 20:3) thou shalt have no other gods before me (1 Tim 6:10, Ps 73:12, Dan 5:4) which was a big problem for this guy – the 2nd (Ex 20:4-6) though it doesn’t seem that he was having trouble with that one – the 3rd (Ex 20:7) he had a little trouble with it when he called Jesus “good” [which should have only been applied to him if he believed Jesus were God], the 4th (Ex 20:8-11) remember the Sabbath day to keep it holy, and the 10th (Ex 20:17) thou shalt not covet. Just look at covetousness in Col 3:5. According to that verse, the rich man was having trouble not only with the 10th commandment but with the 2nd commandment [idolatry] as well. This fellow was using the law to justify himself (Gal 2:16; Rom 3:19) which didn’t work because he had broken several commandments (Jas 2:10).

20 – “What lack I yet” – he knew something was missing – Lk 12:15 (a man’s life consisteth not in the abundance of the things which he possesseth) – possessions couldn’t satisfy the emptiness of a life without Christ.

21 – “thou shalt have treasure in heaven” was a promise based upon Matt 6:20 – in other words he could have kept the wealth beyond this life had he believed Jesus and followed him

22 – “sorrowful” Ps 49:6-9. The man’s problem wasn’t the possession of so much wealth; his problem was that he was trusting that wealth to take care of him [trust in riches Mk 10:24]

23 – “a rich man shall hardly enter in” – he can’t at all if he is trusting his riches because riches obscure faith.

24 – “easier for a camel to go through the eye of a needle” – this is not the “needle gate” as some say. This is a literal statement to demonstrate the “impossible,” (v.26). It is impossible for a rich man who trusts his riches to get into the kingdom.

25 – “who then can be saved?” – the disciples asked this question because in the Old Testament, God increased the riches of those he blessed – Abraham (Gen 13:2), Isaac 100 fold (Gen 26:12-14), Jacob (Gen 40:43), Solomon (2 Chr 1:12), and he doubled Job’s possessions (Job 42:12) – their question really demonstrates the fact that they were living in the transition period from the Old Testament to the New Testament – Jesus and the disciples didn’t have much in the way of possessions but they had eternal life which this man didn’t have with all of his possessions

26 – “with God all things are possible” – here he’s referring to the free gift of eternal life in Jesus Christ which no man can attain without the New Birth