2-peter 2:20

The pollutions of the world - Sin in general, and particularly superstition, idolatry, and lasciviousness. These are called μιασματα, miasmata, things that infect, pollute, and defile. The word was anciently used, and is in use at the present day, to express those noxious particles of effluvia proceeding from persons infected with contagious and dangerous diseases; or from dead and corrupt bodies, stagnant and putrid waters, marshes etc., by which the sound and healthy may be infected and destroyed. The world is here represented as one large, putrid marsh, or corrupt body, sending off its destructive miasmata everywhere and in every direction, so that none can escape its contagion, and none can be healed of the great epidemic disease of sin, but by the mighty power and skill of God. St. Augustine has improved on this image: "The whole world," says he, "is one great diseased man, lying extended from east to west, and from north to south; and to heal this great sick man, the almighty Physician descended from heaven." Now, it is by the knowledge of the Lord and Savior Jesus Christ, as says St. Peter, that we escape the destructive influence of these contagious miasmata. But if, after having been healed, and escaped the death to which we were exposed, we get again entangled, εμπλακεντες, enfolded, enveloped with them; then the latter end will be worse than the beginning: forasmuch as we shall have sinned against more light, and the soul, by its conversion to God, having had all its powers and faculties greatly improved, is now, being repolluted, more capable of iniquity than before, and can bear more expressively the image of the earthly.

For if after they have escaped the pollutions of the world - This does not necessarily mean that they had been true Christians, and had fallen from grace. People may outwardly reform, and escape from the open corruptions which prevail around them, or which they had themselves practiced, and still have no true grace at heart.

Through the knowledge of the Lord and Saviour Jesses Christ - Neither does This imply that they were true Christians, or that they had ever had any saving knowledge of the Redeemer. There is a knowledge of the doctrines and duties of religion which may lead sinners to abandon their outward vices, which has no connection with saving grace. They may profess religion, and may Know enough of religion to understand that it requires them to abandon their vicious habits, and still never be true Christians.

They are again entangled therein and overcome - The word rendered "entangled," (ἐμπλέκω emplekō,) from which is derived our word "implicate," means to braid in, to interweave; then to involve in, to entangle. It means here that they become implicated in those vices like an animal that is entangled in a net.

The latter end is worse with them than the beginning - This is usually the case. Apostates become worse than they were before their professed conversion. "Reformed" drunkards, if they go back to their "cups" again, become more abandoned than ever. Thus, it is with those who have been addicted to any habits of vice, and who profess to become religious, and then fall away. The "reasons" for this may be:

(1) that they are willing now to show to others that they are no longer under the restraints by which they had professedly bound themselves;

(2) that God gives them up to indulgence with fewer restraints than formerly; and,

(3) their old companions in sin may be at special pains to court their society, and to lead them into temptation, in order to obtain a triumph over virtue and religion.

2:20 For if after they - Who are thus ensnared. Have escaped the pollutions of the world - The sins which pollute all who know not God. Through the knowledge of Christ - That is, through faith in him, 1:3 .They are again entangled therein, and overcome, their last state is worse than the first - More inexcusable, and causing a greater damnation.