A.T. Robertson Commentary James 1:4

"And let patience have [its] perfect work, that ye may be perfect and entire, lacking in nothing." — James 1:4 (ASV)

Let have (εχετω). Present active imperative of εχω, let it keep on having.

Perfect (τελειον). See Ro 5:3f. for a like chain of blessings. Carry on the work to the end or completion (from τελος, end) as in Joh 17:4 (το εργον τελειωσας, having finished the work).

That ye may be (ινα ητε). Purpose clause with ινα and present active subjunctive of ειμ. This is the goal of patience.

Perfect and entire (τελειο κα ολοκληρο). Perfected at the end of the task (τελος) and complete in all parts (ολοκληρο, ολος whole and κληρος lot or part). "Perfected all over." These two adjectives often occur together in Philo, Plutarch, etc. See Ac 3:16 for ολοκληριαν (perfect soundness).

Lacking in nothing (εν μηδεν λειπομενο). Present passive participle of λειπω to leave. Negative statement of the preceding positive as often in James (cf. 1:6). There is now a digression (verses 5-8) from the discussion of πειρασμος, which is taken up again in verse 9. The word λειπομενο (lacking) suggests the digression.