Thomas Brooks emphasizes the distinction between occasional sinning and a lifestyle of sin, asserting that a true saint may stumble but does not embrace sin as a way of life. He illustrates that while a godly person may temporarily stray, their primary focus is on departing from iniquity, much like a traveler who occasionally veers off course. Brooks reassures believers that if sin is their burden, it will not lead to eternal condemnation, as God reserves hell for those who find pleasure in sin. He compares sin in a saint to poison in the body, highlighting the discomfort it brings and the desire to expel it. Ultimately, a sincere Christian's heart is set on overcoming sin, ensuring they will not face eternal misery for their transgressions.

It is one thing for a man to sin, it is another thing for a man to allow himself in sin. It is one thing for a godly man to step into a sin, and it is another thing to keep the road of sin. A real saint can neither allow of sin, nor wallow in sin, nor be transformed into the image of sin, nor mix itself with sin. It is possible for a sincere Christian to step into a sinful path, or to touch upon sinful facts, and now and then in an hour of temptation, to slide, to trip, and to be overtaken unawares. But his main way, his principal work, is to depart from iniquity; as a true traveler may now and then step a few steps out of his way—who yet for the main keeps his way, keeps the road. Or as a bee may now and then light upon a thistle—but her main work is to be gathering at the flowers. Or as a sheep may now and then slip into the dirt, or into a slough—but its main work is to be grazing upon the mountains. Certainly, O soul, if sin is now your greatest burden, it shall never hereafter prove your eternal bane. God never yet sent any man to hell for sin, to whom sin has commonly been the greatest hell in this world. God has but one hell, and that is for those to whom sin has been commonly a heaven in this world. That man who hates sin, and who daily enters his protest against sin—that man shall never be made miserable by sin. Sin in a wicked man is like poison in a serpent; it is in its natural place, it is delightful to a sinner. But sin in a saint is like poison in a man's body, it is offensive, and the heart rises against it, and uses all divine antidotes whereby it may be expelled and destroyed. Nothing will satisfy a gracious soul—but the heart blood of his lusts. Now, he shall never be damned for his sins, whose heart is set upon killing his sins.