They never atone for one sin
We allow further that the use of all means whatever will never atone for one sin. It is the blood of Christ alone by which any sinner can be reconciled to God. There is no other propitiation for our sins, no other fountain for sin and uncleanness.
Every believer in Christ is deeply convinced that there is no merit but in him, that there is no merit in any of his own works: not in uttering the prayer, or searching the scripture, or hearing the word of God, or eating of that bread and drinking of that cup.
So if no more is intended by the expression some have used, Christ is the only means of grace, than this, that he is the only meritorious cause of it, it cannot be gainsaid by any who know the grace of God.
1771 text
4. We allow farther, that the use of all means whatever, will never atone for one sin; that it is the blood of Christ alone, whereby any sinner can be reconciled to God; there being no other propitiation for our sins, no other fountain for sin and uncleanness. Every believer in Christ is deeply convinced, that there is no merit, but in him: that there is no merit in any of his own works; not in uttering the prayer, or searching the scripture, or hearing the word of God, or eating of that bread and drinking of that cup. So that if no more be intended by the expression some have used, “Christ is the only means of grace,” than this, that he is the only meritorious cause of it, it cannot be gain-said by any who know the grace of God.