Charles H. Spurgeon on Psalms 18:18

"They prevented me in the day of my calamity: but the Lord was my stay." When Henry the Eighth had spoken and written bitterly against Luther; said Luther, Tell the Henries, the bishops, the Turks, and the devil himself, do what they can, we are the children of the kingdom, worshipping of the true God, whom they, and such as they, spit upon and crucified. And of the same spirit were many martyrs. Basil affirms of the primitive saints, that they had so much courage and confidence in their sufferings, that many of the heathen seeing their heroic zeal and constancy, turned Christians. —Charles Bradbury.

Verse 20 "The Lord rewarded me according to my righteousness; according to the clearness of my hands hath he recompensed me." We must stand our ground, and be stiff for ourselves against all misjudgings. It is good to be zealously affected always in a good matter, whether it respects the glory of God immediately and alone, or whether it respects the credit of our brethren or our own. To desire to be famous in the world, and as those giants in the old world (Genesis 6:4), men of renown, or, as the original text hath it, men of name, is a very great vanity; but to protect and preserve our good name is a great and necessary duty. —Joseph Caryl.

Verse 21 "I have not wickedly departed from my God;" that is, with a purpose and resolution of heart to continue in a way of sinning; and that is the property of sincerity. A man may indeed be overtaken and surprised by a temptation, but it is not with a resolution to forsake God and to cleave unto the sin, or rest in it. He will not sleep in it, spare it, or favour it; that is, to do wickedly against God, to have a double heart and a double eye; to look upon two objects, partly at God and partly at sin; so to keep God, as to keep some sin also, as it is with all false-hearted men in the world. They look not upon God alone, let them pretend to religion never so much, yet they look not unto God alone, but upon something else together with God; as Herod regarded John, but regarded his Herodias more; and the young man in the gospel, comes to Christ, yet he looks after his estate; and Judas followed Christ, yet looks after the bag; this is to depart wickedly from God. —William Strong, 1650.

Verse 21 (last clause). Although a godly man may break a particular commandment again and again against knowledge, yet his knowledge never suffers him to go so far as to venture knowingly to break the covenant of grace with God, and to depart from him; when he hath gone on so far in a sin as he comes to apprehend he must break with God, and lose him if he goes any further, this apprehension stays him, stops and brings him back again; he may presumptuously venture (though seldom; and always to his cost) to commit an act of sin against knowledge, because he may withal think, that by one act the covenant is not broken, nor all friendship and love hazarded between God and him, nor his interest in the state of grace, nor God, quite lost by it, though he may well think he would be displeased with him; but if he should begin to allow himself in it, and to continue to go on again and again in it, then he knows the covenant would be broken, it cannot stand with grace; and when this apprehension comes, and comes in strongly, he cannot sin against it, for this were to cast away the Lord, and to depart wickedly from him, now so he doth not. So David, though he sinned highly and presumptuously, yet says he, "I have not departed wickedly from my God;" that is, I have not so far departed from him as though I apprehended I should utterly lose my interest in him, yet I would go on. No; for he is my God, there lies the consideration that kept him from departing from him. So Psalm 44:17, "We have not dealt falsely in thy covenant," says the church there. Many acts of displeasing him may pass and be ventured, but if the holy soul thinks that the covenant lay at stake, that he and God must utterly part and break off, thus far he will never go. —Thomas Goodwin.