4:18 If the righteous scarcely be saved, where shall the ungodly and the sinner appear? A passage quoted from Pr 11:31. The idea is that if sufferings and judgments (chastenings) come upon good people, what hope is there for the wicked?
4:18 If the righteous scarcely be saved - Escape with the utmost difficulty. Where shall the ungodly - The man who knows not God. And the open sinner appear - In that day of vengeance. The salvation here primarily spoken of is of a temporal nature. But we may apply the words to eternal things, and then they are still more awful. Prov 11:31.
4:12-19 By patience and fortitude in suffering, by dependence on the promises of God, and keeping to the word the Holy Spirit hath revealed, the Holy Spirit is glorified; but by the contempt and reproaches cast upon believers, he is evil spoken of, and is blasphemed. One would think such cautions as these were needless to Christians. But their enemies falsely charged them with foul crimes. And even the best of men need to be warned against the worst of sins. There is no comfort in sufferings, when we bring them upon ourselves by our own sin and folly. A time of universal calamity was at hand, as foretold by our Saviour, Mt 24:9,10. And if such things befall in this life, how awful will the day of judgment be! It is true that the righteous are scarcely saved; even those who endeavour to walk uprightly in the ways of God. This does not mean that the purpose and performance of God are uncertain, but only the great difficulties and hard encounters in the way; that they go through so many temptations and tribulations, so many fightings without and fears within. Yet all outward difficulties would be as nothing, were it not for lusts and corruptions within. These are the worst clogs and troubles. And if the way of the righteous be so hard, then how hard shall be the end of the ungodly sinner, who walks in sin with delight, and thinks the righteous is a fool for all his pains! The only way to keep the soul well, is, to commit it to God by prayer, and patient perseverance in well-doing. He will overrule all to the final advantage of the believer.
