Greek: θρησκεία καθαρὰ καὶ ἀμίαντος παρὰ τῷ θεῷ καὶ πατρὶ αὕτη ἐστίν, ἐπισκέπτεσθαι ὀρφανοὺς καὶ χήρας ἐν τῇ θλίψει αὐτῶν, ἄσπιλον ἑαυτὸν τηρεῖν ἀπὸ τοῦ κόσμου. (WH 1885)
"Pure religion and undefiled before our God and Father is this: to visit the fatherless and widows in their affliction, and to keep oneself unstained by the world" (WEB).
"The form of worship that is clean and undefiled from the standpoint of our God and Father is this: to look after orphans and widows in their tribulation, and to keep oneself without spot from the world" (NWT 2013)
From Dan G. McCartney's James Commentary in the Baker Exegetical Series: The verb “to look after” (ἐπισκέπτομαι, episkeptomai) carries several possible connotations. In the Greek OT it was used to translate the Hebrew pāqad, which could mean “to visit” or “to bring justice to,” and both these meanings can also be found in the NT (e.g., Luke 1:68; Acts 15:36). It can also mean “to care for” (Heb. 2:6) or “to seek out” (Acts 6:3) or “to concern oneself with” (Acts 15:14). Any of these meanings work well here. The most common meaning in the NT is “to go see a person with helpful intent” (BDAG 378). It is the motive of helpful intent, the objective of giving aid, or undertaking to look out for the interests of someone that is operative here. Given James’s concern that people do things for the needy rather than just say things to them (2:16), it is unlikely that James has only visitation or an intellectual interest in mind here.
From Scot McKnight's James Commentary in The New International Commentary on the New Testament Series:
ἐπισκέπτεσθαι, see BDAG, 378. The term is cognate with ἐπίσκοπος. The present tense indicates vivid or characteristic action and behavior. The infinitive defines αὕτη and thus functions as a complement of the predicate. It is structurally equivalent with τηρεῖν at the end of 1:27.