William Burkitt on Matthew 19:16

Observe here, A person addressing himself to Christ, and propounding an important question to him; namely, What he should do to gain eternal life?

Where, Note, 1. He believes the certainty of a future state.

2. He professes his desire of an eternal happiness in that state.

And, 3. He declares his readiness to do some good, that he may obtain that happiness.

Learn, That the light of nature, or natural religion, directs and teaches men, that good works are necessary to salvation, or that some good things must be done by men that at death expect eternal life.

What good thing shall I do that I may have eternal life? It is not talking well, and professing well, but doing well, and living well, that entitles us to eternal life.