“This is followed by a perfect man. The man himself is characterized from his condition and work” (Bengel). Work (ἔργον) is the word with which κατεργάζεται, worketh, is compounded. It is the accomplished result of patience in moral purification and ennobling. Compare work of faith, 1Th 1:3.
Perfect and entire (τέλειοι καὶ ὁλόκληροι)
The two words express different shades of thought. Τέλειοι, perfect, from τέλος, fulfilment or completion (perfect, from perfectus, per factus, made throughout), denotes that which, h has reached its maturity or fulfilled the end contemplated. Ολόκληροι, from ὅλος, entire, and κλῆρος, a lot or allotment; that which has all which properly belongs to it; its entire allotment, and is, therefore, intact in all its parts. Thus Peter (Act 3:16) says of the restored cripple, “faith has given him this perfect soundness (ὁλοκληρίαν). Compare the familiar phrase, an accomplished man. Note, also, James' repetition of the key-words of his discourse, rejoice, joy, patience, perfect.
Wanting nothing (ἐν μηδενὶ λειπόμενοι)
Rev., more literally, lacking in nothing. Note James' characteristic corroboration of a positive statement by a negative clause: entire, lacking in nothing ; God that giveth and upbraideth not; in faith, nothing doubting. The conditional negative μηδενὶ, nothing, is used, rather than the absolute negative οὐδενὶ, as implying nothing which may be supposed ; no possible thing.