“Be diligent” means “give special care” or “take pains” with your task. 1 Timothy 4:16 continues with similar intensity:
Keep a close watch on yourself and on the teaching. Persist in this, for by so doing you will save both yourself and your hearers (1 Timothy 4:16).
Pay careful attention – “watch closely!” Keep striving – “persevere!”19 These activities are vital to “save” both the Christian messenger and those who hear him. We might think, “Of course Timothy had to be careful; he was a leader at Ephesus.” Yet Paul gave similar instructions to all the members at Ephesus:
Look carefully then how you walk, not as unwise but as wise, making the best use of the time, because the days are evil (Ephesians 5:15-16). M
Later, Jesus found Ephesian members less diligent than they should have been. He sternly charged them, “repent, and do the works you did at first” (Revelation 2:5). In that verse, Jesus’ wording is literally, “Do the first works!”
All of this raises questions about works. Why must believers work in such a determined way? Why be “very careful” – especially when Jesus has taken care of everything for us? Ephesians itself emphasizes that we cannot earn favor with God by our works. Salvation is a gift of grace received through faith (Ephesians 2:8-9).20
19. Research Subject – Persevering: Matthew 10:22; 24:13; Luke 8:15; 21:19; Colossians 1:23; Romans 11:22; 1 Timothy 4:16; Revelation 2:10
20. Romans 4:1-8,16; 5:1-2 cf. Galatians 2:16-21; 3:8-14,22-27; 5:4