The belief of the Truth alone is the cause of all true holiness; while our good works simply help our neighbor

"The simple belief of the truth, is the only spring of all true holiness, of all love and obedience to God. He who, perceiving the Divine love to sinners of all sorts, without distinction, manifested in the atonement, is thereby led to love the atonement, and the Divine character appearing there, and so to enjoy the promised comfort resulting thence to the obedient, comes at the same time to know his particular interest in the atonement. And thus by happily experiencing the truth of the gospel, he is greatly encouraged to go forward in that course into which he was at first introduced by the evidence of truth appearing to him in the report of the gospel. So he labours neither first nor last to acquire any requisite to justification; but all his labour proceeds on the persuasion, that the atonement itself is the sole and all-sufficient requisite to justification. He is likewise sensible, that the atonement is the sole spring of all his self-denied love, and of all the present comfort, as well as future reward connected with it; so he knows that all his holiness, as well as all his happiness, comes entirely of that grace which provided the atonement, and thus he understands how grace reigns through righteousness unto eternal life." - Robert Sandeman, Letters on Theron and Aspasio

"In the sight of God it is really faith that makes a person holy; faith alone serves him, while our works serve the people." - Martin Luther, The Large Catechism, in The Book of Concords, pg. 385

"Some then may object, if it be so, we ought to refrain from doing righteousness, as from dung.
I answer, It follows not; but that we must refrain from glorying in, or stroaking ourselves for our righteous doings, and rather take shame to ourselves when we have done, and so glory only in the Lord. Though good works done by us are but dung in themselves, and in God's eye; yet must we be careful to maintain them, since they are profitable to men, Tit. iii. 8. David (Psal. xvi. 2, 3,) confesseth, that his goodness extendeth not to God; yet for all this he refrains not, because it could extend to the Saints upon earth, and to the excellent in whom was his delight; it is no good plea, that because a man cannot be wholly clean, therefore, he will be more filthy than needs. . . ." - Tobias Crisp, Christ Alone Exalted, Second Volume, Pg. 42