A.T. Robertson Commentary 1 Timothy 4:15

"Be diligent in these things; give thyself wholly to them; that thy progress may be manifest unto all." — 1 Timothy 4:15 (ASV)

Be diligent in these things (ταυτα μελετα). Old verb from μελετη (care, practice), present active imperative, "keep on practising these things." In N.T. only here and Ac 4:25.

Give thyself wholly to them (εν τουτοις ισθ). Present imperative second person singular of ειμ, "keep on in these things." Note five uses of εν in verse 12 and three datives in verse 14. Plutarch (Pomp. 656 B) says Caesar was εν τουτοις ("in these things"). It is like our "up to his ears" in work (ιν μεδιας ρες) and sticking to his task.

Thy progress (σου η προκοπη). Koine word from προκοπτω, to cut forward, to blaze the way, in N.T. only here and Php 1:12,25. Paul's concern (purpose, ινα and present subjunctive η of ειμ) is that Timothy's "progress" may be "manifest to all." It is inspiring to see a young preacher grow for then the church will grow with him.