Charles H. Spurgeon on Psalms 37:37

The perfect man, etc. —Divines well distinguish of a double perfection, it is absoluta or comparata. That is absolutely perfect, to which nothing (that it may be accounted truly good) is wanting; and thus He only is perfectus who is infactus; God, who made all things, and himself is not made, only enjoying an all sufficient perfection, in and of himself. That is comparatively perfect, in which, notwithstanding some wants there is a fulness compared with others. Thus every saint is perfect in comparison of the wicked among whom he liveth. In this respect it is said of Noah, That he was a perfect man in his generations; his grace compared with the wickedness of the old world well deserving the name of perfection; indeed every upright man is perfect in comparison of them who are openly bad, or but openly good; stained with wickedness, or but painted with holiness. Thus one saint may be perfect if compared with another, the strong Christian in respect of the weak, whom he outstrips in grace and piety: such saints Paul means when he saith, "We speak wisdom among them that are perfect; " that is, such as have attained to greater measures of grace than others. It was said of Benaiah, "He was more honourable than thirty, but he attained not to the first three; "and though no saint can ever attain to the perfections of the first three, the blessed Trinity, yet many saints may be honourable amongst thirty perfect in comparison of those among whom they live.

We must further distinguish of a double perfection, it is extrinseca and intrinseca. Extrinsic perfection so called, because by imputation, is that which every believer is partaker of through the perfect righteousness of Christ, whereby all his imperfections are covered; in this respect the author to the Hebrews tells us, "That by one offering he hath perfected for ever them that are sanctified; "and S. Paul tells the Colossians that they were "complete in him, "meaning Christ. Indeed omnia Dei mandata tune facta deptutantua, quando id quod non fit ignoscitur: divine commands are then in God's account fulfilled when our defects for Christ's sake are pardoned; and the evangelical perfection of a Christian consists not in perfectione virtutum, sed remissions vitiorum, in the completion of our graces, but remission of our sins.

Intrinsical perfection, so called because by inhesion, is no less rationally than usually thus distinguished, there is perfectio partium et graduum. He is said to be perfect, cui nihil deest eorum quae ad statum salutis necessaria, who wants no graces that accompany salvation; or he is perfect, cui nihil deest in gradibus gratiarum et virtutum; who is not defective in the measures of those graces; both these are frequently and fitly illustrated by the resemblance of a child, and a grown man; the one whereof hath all the essential and integral parts of a man, the other a complete use and measure of those parts. Nathaniel Hardy.