Deuteronomy 32:4 He is the Rock, his works are perfect, and all his ways are just. A faithful God who does no wrong, upright and just is he.When a person becomes a Christian by the grace of God alone (Eph. 2:8-10) he indeed does change (2 Cor. 5:17), however he or she does not become "perfect" immediately (Eph. 4:7, 12-13, etc.). Only at death (Phil. 1:23) or in the last days when Christians are glorified (1 Cor. 15:42 f) and come to perfect rest with God himself will they be perfect and unable to be hypocritical, jumped up snobs, and assorted other things (Rom. 3:23; Eph. 2:3) that are despicable especially to God.
2 Samuel 22:31-33 "As for God, his way is perfect; the word of the LORD is flawless. He is a shield for all who take refuge in him. For who is God besides the LORD? And who is the Rock except our God? It is God who arms me with strength and makes my way perfect.
Job 37:16 Do you know how the clouds hang poised, those wonders of him who is perfect in knowledge?
While I would not agree that "all" Christians are hypocritical and jumped up snobs, many unfortunately are. However, it is even worse than what many have observed as Christians in the past (and present) are and have been: (1) murderers (2 Sam. 11-12, David sent Uriah to his death), (2) liars (Gen. 27:14-24, Jacob's lies), and (3) adulterers (2 Sam. 11-12, David and Bathsheba), etc. So, most now would ask how are these people and these types of people Christians at all?
The answer lies in our understanding that individuals become Christians not because they have lived such a good life or are in anyway worthy of such an honor (Rom. 9:11-13), but because of God's grace alone (Rom. 9:15-16, 23). See, where sins abounds, grace does much more abound (Rom. 5:20). Though a Christian's sins are great and varied (Rom. 3:10-18; Ex. 20:1-15; Deut. 5:6-21, etc.), Christ's perfection and His grace are still more plentiful. Though there has been great sin, there has been even a greater and more perfect sacrifice that of the Son of God himself (Heb. 2:10; 5:9; 9:11). See, for the true Christian though he will "sin less" as he progresses in his individual journey, he will not be "sinless" until later (death or at the return of Christ)!
Some of course will attempt to misuse this marvelous truth and continue to sin more and more (Rom. 6:15, Antinomianism). However, these merely prove that they were never true recipients of grace in the first place (Rom. 6:16; Mark 4:13-19). The true recipient of grace though he blows it at times and blows it bad, like David (see references above) or Peter who denied Christ (Mark 14:66-72), etc. still has within himself a new nature (2 Pet. 1:4) to desire to want to do good (Rom. 6:17 f).
May God give the reader grace and mercy as the Holy Spirit applies His message to the soul.
Theological Editor of Third Millennium Ministries, (IIIM)