Philippians 3:8

Yea, doubtless, and I count all things [but] loss
Not only the things before mentioned, but anything, and everything else but Christ, or that stood in competition with him, or were short of him; as his natural and acquired parts; the whole compass of learning he had attained to; all that honour, credit, reputation, and popularity he was in for knowledge and devotion; all worldly substance, the comforts of life, and life itself; and all his righteousness since conversion, as well as before; of this no doubt could be made by those who knew him, his principles and his practices: and all this

for the excellency of the knowledge of Christ Jesus my Lord:
"by the knowledge of Christ" is not meant subjectively the knowledge that is in Christ, or which he has of others, either as God or man; but objectively, that knowledge which believers have of him, who know him not only in his person, as God over all, but as a Saviour and Redeemer, and as theirs; they know him in all his relations, and particularly as their Lord, not by creation only, but by redemption and grace, as the apostle did, putting an emphasis on these words, "my Lord"; thereby expressing his faith of interest in him, his great affection for him, and cheerful subjection to him. And this knowledge is not general, but special, spiritual, and saving; it is a knowledge of approbation of Christ above all others; a fiducial one, which has faith in him joined with it, and is both experimental and, practical, and, at least at times, appropriating; and though imperfect, it is progressive and capable of being increased, and will at last be brought to perfection. It is attained to, not by the light of nature, nor by the help of carnal reason, nor by the law of Moses, but by the Gospel of the grace of God, as a means; and the efficient cause of it is Father, Son, and Spirit; the Father reveals Christ in his saints; the Son gives them an understanding to know him; and the Spirit is a spirit of wisdom and revelation in the knowledge of him; and this knowledge is very excellent: a spiritual knowledge of Christ is more excellent than a general and notional one, or than a knowledge of Christ after the flesh; and the knowledge of Christ under the Gospel dispensation, though the same in nature, is more excellent than that which was under the legal dispensation, by promises, prophecies, and the ceremonial law, in degree, extensiveness, and clearness; but the most excellent knowledge of Christ is that of the saints in heaven; yea, even there is an excellency in what the saints have here on earth, and a superior one to all other knowledge, if the author and original of it is considered: it is not of ourselves, nor by the assistance of men; it is not in the book of nature, nor in the schools of the philosophers; it is not of earth, nor earthly, but it comes from afar, from above, from heaven, from God the Father of lights; it is a free grace gift, a distinguishing one, and is very comprehensive, unspeakable, and unchangeable: and as to the object of it, it is Christ, the chiefest among ten thousands; who made the heavens, earth, and seas, and all that in them are, the sun, moon, and stars, men and beasts, birds and fishes, fossils, minerals, vegetables, and everything in nature; and therefore the knowledge of him must be superior to the knowledge of everything else; and, which adds to its excellency, it makes Christ precious, engages faith and confidence in him, influences the life and conversation, humbles the soul, and creates in it true pleasure and satisfaction; when all other knowledge fills with self-love, pride, and vanity, and increases sorrow; whereas this is not only useful in life, but supports, as under afflictions, so in the views of death and eternity; through it grace is received now, and by it glory hereafter; for it is the beginning, earnest, and pledge of eternal life. Well may the believer count all things but loss for it, as the apostle did; who adds, for further confirmation of what he had asserted,

for whom I have suffered the loss of all things;
he dropped all confidence in his carnal privileges, and civil, ceremonial, and moral righteousness, for Christ and his righteousness; he parted with all for this pearl of great price; he lost his good name, credit, and reputation among men, and suffered afflictions and persecutions in various shapes; he lost the comforts of life, being often in cold and nakedness, in hunger and thirst, and was ready to suffer the loss of life itself for professing and preaching Christ:

and do count them [but] dung;
or dog's meat; see ( Philippians 3:2 ) ; what is fit only to be cast to dogs, as the word signifies; and intends every thing that is base, mean, and worthless; as the faeces of men, the dregs and lees of liquor, the falling of fruit, chaff, stubble, the dross of metals, dung, and what not: so he esteemed his carnal descent; his form and sect of religion, and zeal in it; his ceremonial and moral righteousness before and after conversion; and everything of the creature, or what was his own, and but flesh; being of the same opinion with the church of old, who reckoned her righteousnesses, the best, and the whole of them, as "filthy rags". The apostle next expresses his end and views in this,

that I may win Christ;
not get an interest in him, for this he had already, and he knew he had, and that he should never lose it; and besides, an interest in Christ is not a thing that begins in time, but commenced from all eternity; and is not gotten at all, not by good works, nor repentance, nor faith; for these, if right and genuine, are the fruits and effects of an interest in Christ, but is what is freely given. The apostle's meaning is, either that he might gain or acquire a larger knowledge of Christ; and he cared not what pains he took, what expenses he was at, nor what loss he sustained for what he esteemed the most excellent, and for which he had already suffered the loss of all things; and if he had had more to lose, he could willingly part with it for more of this knowledge; compare ( Philippians 3:10 ) ; or his sense is, that he might gain by Christ, or that Christ might be gain to him, as he found him to be, and as he is to every believer; who by parting with all for Christ, gains much by him, as a justifying righteousness, acceptance with God, peace, pardon, life, grace, and glory.