James 1:27

Pure religion and undefiled
That which is sincere and genuine, and free from adulteration and hypocrisy:

before God and the Father;
or in the sight of God the Father of Christ, and all his people; that which is approved of by him, who is the searcher of hearts, and the trier of the reins of men, "is this": not that the apostle is giving a full definition of true religion; only he mentions some of the effects of it, by which it is known, and without which it cannot be true and genuine; and they are these:

to visit the fatherless and widows in their affliction;
and not only to see them, and speak a word of comfort to them, but to communicate to them, and supply their wants, as they may require, and according to the ability God has given: where there is true religion in the heart, there is love to God; and where there is love to God, there is love to the saints; and this will show itself to them, in times of affliction and distress; and where this is wanting, religion itself is not pure and undefiled:

and to keep himself unspotted from the world:
from the men of the world, who defile by their evil communications; and "from the vices of the world", as the Arabic version renders it, which are of a defiling nature; and, where religion is in its power and purity, and the Gospel of the grace of God comes with efficacy, it teaches to separate from the rest of the world, and to deny ungodliness and worldly lusts, and to live soberly, righteously, and godly.