Know, for a ground of this, that in the covenant of grace, God requires the truth of grace, not any certain measure; and a spark of fire is fire as well as the whole element. Therefore we must look to grace in the spark as well as in the flame. All have not the like strong, yet the like precious faith, 2 Pet. 1:1, whereby they lay hold, and put on, the perfect righteousness of Christ. A weak hand may receive a rich jewel; a few grapes will shew that the plant is a vine, and not a thorn. It is one thing to be wanting in grace, and another thing to want grace altogether. God knoweth we have nothing of ourselves, therefore in the covenant of grace he requireth no more than he giveth, and giveth what he requireth, and accepteth what he giveth: ‘He that hath not a lamb may bring a pair of turtle doves,’ Lev. 12:6. What is the gospel itself but a merciful moderation, in which Christ’s obedience is esteemed ours, and our sins laid upon him, and wherein God of a judge becometh the father, pardoning our sins and accepting our obedience, though feeble and blemished! We are now brought to heaven under the covenant of grace by a way of love and mercy.

Sibbes, R. (1862). The Complete Works of Richard Sibbes. (A. B. Grosart, Ed.) (Vol. 1, p. 58). Edinburgh; London; Dublin: James Nichol; James Nisbet and Co.; W. Robertson.