The Bible is plain that God requires moral perfection. It tells us unambiguously that God is holy and therefore cannot tolerate any hint of unholiness. Defects, blemishes, or stains–to the smallest degree–are unacceptable and deserving of God’s wrath. And just in case I’m deluded enough to think that my Spirit-wrought moral improvement since I became a Christian is making the grade, Jesus (in the Sermon on the Mount) intensifies what God’s required perfection entails: “Not only external actions but internal feelings and motives must be absolutely pure. Jesus condemns not only adultery but lust, not only murder but anger–promising the same judgment for both” (Gene Veith).
In Matthew 5-7, Jesus wants us to see that regardless of how well we think we’re doing or how much better we’re becoming, when “You therefore must be perfect, as your heavenly Father is perfect” becomes the requirement and not “look how much I’ve grown over the years”, we begin to realize that we don’t have a leg to lean on when it comes to answering the question, “How can I stand righteous before God”? Our transformation, our purity, our growth in godliness, our moral advances and spiritual successes–Spirit-animated as it all may be–simply falls short of the sinlessness God demands. And since a “not guilty verdict” depends on sinlessness, assurance is ultimately contingent on perfection, not progress.
So, if God requires perfection and there is no definitive assurance without it (God isn’t grading on a curve, after all), then what hope do I have, imperfect as I am?
The New Testament answer to this question is singular:
For in the gospel a righteousness from God is revealed, a righteousness that is by faith from first to last, just as it is written: “The righteous will live by faith.” (Romans 1:17) For all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus, whom God put forward as a propitiation by his blood, to be received by faith. (Romans 3:23-25) And to the one who does not work but believes in him who justifies the ungodly, his faith is counted as righteousness. (Romans 4:5) The conscience is given assurance only as living faith is created by the Spirit through the Gospel announcement that God justifies the ungodly. The righteousness we need comes from God “through faith in Jesus Christ to all who believe.” (Romans 3:22)