“Why do you ask me about that which is good.” For an explanation of Jesus’ answer, see commentary on Matthew 19:16. This verse reads differently in some of the English versions such as the KJV. For example, in the KJV, Matthew 19:17 reads basically the same as Mark 10:18 and Luke 18:19. Historically, scribes disliked when the Gospel records read differently, and so they “adjusted” the text so that they read the same way. Textual scholars refer to this tendency as “harmonization,” and it occurs a number of times in the over 5,700 manuscripts of the New Testament extant today, but in most cases, the change to a manuscript is caught before it ever gets into an English version. The scribes harmonized the text, sometimes on purpose, sometimes because they were copying from memory and simply mistakenly copied what they remembered from another place in the Bible. In any case, in this instance in Matthew, the textual evidence from the early manuscripts clearly points to the fact that Greek text and the reading that is based upon it in the REV and almost all modern English versions is the reading of the original manuscript of Matthew.
“life in the age to come.” This refers to “everlasting life,” the life in the Age to Come, which is the future Millennial Kingdom of Christ on earth. We know that from the previous verse, when the young man wanted to know what to do to have “life in the age to come.” See commentary on Luke 10:28.
“keep the commandments.” Before the Day of Pentecost and the start of the Christian Church, salvation was by faith that was demonstrated by works. There was an interplay between them that is hard to exactly know but it is clearly there. Comparing Acts 16:31 with the time before the Administration of Grace shows us the dramatic change that occurred when the Administration of the Law came to an end and the Administration of Grace began (this change occurred on the Day of Pentecost in Acts 2). Under the Law, to be saved a person had to have faith, but that faith had to be expressed outwardly in the way the person lived. Under the Law, and until the Day of Pentecost, being “born again” was not yet available, neither was being sealed with holy spirit or being guaranteed salvation; God started those things in the Grace Administration. We can clearly see this when we compare Acts 16:30-31 with Matthew 19:16-17 (see commentary on Acts 16:31).