Measure Yourself Accurately

Thomas à Kempis The Imitation of Christ

Let not thy peace depend on the tongues of men, for whether they judge well or ill, thou art not on that account other than thyself.

The highest and most profitable learning is the knowledge of ourselves.  

Lord, I offer unto Thee all my sins and offences, which I have committed before Thee, from the day wherein I first could sin even to this hour; that Thou mayest consume and burn them, one and all, with the fire of Thy love, and do away all the stains of my sins, and cleanse my conscience from all offences, and restore to me Thy grace, fully forgiving me all, and admitting me mercifully into (your) peace.  

I offer up also unto Thee all that is good in me, though it be very small and imperfect, in order that Thou mayest amend and sanctify it, that Thou mayest make it grateful and acceptable unto Thee, and always be perfecting it more and more; and bring me also, slothful and unprofitable poor creature as I am, to a good and blessed end.  

John Calvin's Commentary

This clause may be rendered, “not to think highly above what it behooves him to think,” that is, of himself. Then what follows, “but to think so as to think rightly,” or modestly. The last verb occurs elsewhere five times; thrice it means “to be of a sane mind,” Mark 5:15, Luke 8:35, 2 Corinthians 5:13; and twice it means “to act prudently,” Titus 2:6; 1 Peter 4:7; or, it may be, in the last passage, “to live temperately.” As it refers here to the mind, it must mean such an estimate of one’s self as is sound, just, and right, such as becomes on who is sound and sane in his mind. Pride is a species of insanity; but humility betokens a return to a sane mind: and an humble estimate of ourselves is the only sound, sane, and right estimate.

John Gill's Commentary on "not to think [of himself] more highly than he ought to think"

...that is, either not to arrogate to himself what does not belong to him, and detract from others, who may have equal, if not superior, abilities to him; or not to glory in what he has, as if he had not received it, and as if it was altogether owing to his own sagacity, penetration, diligence, and industry; or not to search into things too high for him that are out of his reach, and beyond his capacity; though this is not to be understood as discouraging a search into the Scriptures of truth, the more difficult parts of it, and the more knotty points of controversy; but as forbidding inquiry into things not lawful to be searched into, or, if lawful, as requiring such a scrutiny to be made with modesty, and an humble dependence on superior light and assistance, and a discovery of it with humility and lowliness of mind; but to think soberly, according as God hath dealt to every man the measure of faith: such ought to consider that what gifts, abilities, light, and knowledge they have, they have then, not of themselves, but from God; that they have not all faith, and all knowledge, or do not know the whole of the faith of the Gospel only a measure of it, which is dealt out, divided, and parted to every man, some having a greater degree of evangelical light than others; and that all have some, but none all.

Adam Clarke's Commentary

Let no man think himself more or greater than God has made him; and let him know that what ever he is or has of good or excellence, he has it from God; and that the glory belongs to the giver, and not to him who has received the gift.  

Richard Sibbes  The Bruised Reed

We must have two eyes, one to see imperfections in ourselves, the other to see what is good.

Octavius Winslow, Personal Declension and Revival of Religion in the Soul, 1841

https://www.gracegems.org/W/pd0.htm

It is no step towards the recovery of a sickly state, to disguise the worst symptoms of that state from the eye. The mark of true wisdom and skill is, to ascertain the worst of the disease, to probe the depth of the wound. And although such a course may be painful to the patient, it is essential to his thorough recovery. Beloved reader, it is important that thou shouldst know the exact state of thy soul before God.

Be honest with yourself; let there be a thorough, faithful examination of your spiritual condition; let all disguise be removed, the eye withdrawn from the opinion of men, and the soul shut in with God in a close scrutiny of its worst state. The ‘backslider in heart’ (Proverbs 14:14) may deceive himself, he may deceive others, but God he cannot deceive. (Jeremiah 17:10)

J.C. Ryle  Old Paths

Do not suppose the day will ever come when you will find no weak point in your heart, no wanderings in private prayer, no distraction in Bible-reading, no cold desires in the public worship of God, no flesh to mortify, no devil to tempt, no worldly snares to make you fall. The old man within you is yet alive; the world around you is yet full of danger; the devil is not dead. Remember at your best, that a converted sinner is still a poor weak sinner, needing Christ every day.

A.W. Tozer 

        We Travel An Appointed Way

We all know how prone we are to find what we are looking for in the Scriptures and in our own lives. When appraising ourselves, we sometimes unconsciously play up everything favorable to us and conversely play down whatever would put us in an unfavorable light. While considering my own ministry, I have often caught myself magnifying every small victory out of all fair proportion and at the same time alibiing my failures and weaknesses. It is the old trick of seeing what we want to see and closing our eyes to the things we would rather forget...and can result in a completely false estimate of our life and work.