All Christians are commanded to put sin to death (Rom 8:13), but this doesn't mean that Christians are ever expected to be finally rid of sin in this life. Until Christ returns or brings us home, we will always fight against sin, we will always be turning over new rocks in heart to find new (or very old, rather) cockroaches scurrying underneath.
Consider the apostle Paul:
In 55 AD he wrote that he was the "least of all the apostles," (1 Cor 15:9).
In 60 AD he wrote that he was the "least of all the saints," (Eph 3:8).
In 62 AD he wrote that he was "the chief of all sinners" (1 Tim 1:15).
As Paul grew as a Christian, his sense of his own greatness diminished. Christian maturity is not marked by becoming more inflated in your ego, but the exact opposite.
Elsewhere Paul laments: "So I find it to be a law that when I want to do right, evil lies close at hand. For I delight in the law of God, in my inner being, but I see in my members another law waging war against the law of my mind and making me captive to the law of sin that dwells in my members. Wretched man that I am! Who will deliver me from this body of death?" (Rom 7:21-24).
Wherever Paul goes, his sin goes with him, his body of death. This reflects Isaiah's preaching hundreds of years prior, where Isaiah laments: "We have all become like one who is unclean, and all our righteous deeds are like a polluted garment. We all fade like a leaf, and our iniquities, like the wind, take us away," (Isaiah 64:6). Even the best that we have to offer, our righteous deeds, are still sullied with sin. When I give money to charity or take the high road in a tense conversation, it is possible for me to smuggle self-serving motives into the good deed: maybe I want to look impressive, maybe I want to embarrass the other person. There are good, holy desires there as well: I sincerely want to serve the poor, I sincerely want to practice patience and self-control. But we are always a mixture, pure and impure motives can swirl together in our breast.
William Beveridge (1637-1708), the Anglican churchman, explains: "I cannot pray but I sin. I cannot hear or preach a sermon but I sin. I cannot give an alms or receive the sacrament but I sin. Nay, I cannot so much as confess my sins, but my very confessions are still aggravations of them. My repentance needs to be repented of, my tears need washing, and the very washing of my tears needs still to be washed over again with the blood of my Redeemer," (Private Thoughts on Religion, p. 52).
Samuel Davies (1723-1761), a powerfully effective evangelist during the First Great Awakening in America, laments: "I have but little, very little, true religion...Perhaps once in three or four months I preach in some measure as I could wish...It is really an afflictive thought that I serve so good a Master with so much inconstancy...I am at best smoking flax; a dying snuff in the candlestick of his church...The flame of divine love, sunk deep into the socket of a corrupt heart, quivers and breaks, and catches, and seems just expiring at times," (cited in Iain Murray's Revival and Revivalism, p. 30).
We may be tempted to assume that these represent individuals who are in need of a boost in self-esteem or who struggle with an unhealthy negativity. But, Iain Murray rebuts, "These are not the words of a depressive and an introvert. They are the feelings of one who has seen something of the greatness of his Saviour."
And that is the whole point of the story of the sinful woman in Luke 7:36-50. Her tears and groveling at Jesus' feet are not symptoms that she has distorted view of her own self-worth. They are precisely the right response sinners should have to so great a Savior. And it is the very depth of her awareness of her sin that opens up the deepest channels of her experience of the love of God. Our experience of the sweetness of God's love isn't in spite of our sin, but in direct relation to it. God loves us wretches though we are--what glory! He who is forgiven much, loves much--and he who doesn't see much to forgive, will find little love. It was Paul's ever deepening sense of his sinfulness that led him to describe the "overflowing..grace...faith and love that are in Christ Jesus," (1 Tim 1:14).
So, Dane Ortlund reminds us: "You cannot feel the weight of your sinfulness strongly enough." But, it is possible to dwell on the wretchedness of your sin and not bring it to Jesus. That would be a colossal mistake on par with the patient avoiding the doctor because they deem themselves too ill. It is our very illness and misery that drives us to the physician, and likewise it is our very wretched sinfulness that drives us to Jesus, the friend of sinners.
So, Ortlund concludes: "As you despair of yourself--agonizing over the desolation wrought by your failures, your weaknesses, your inadequacies--let that despair take you way down deep into honesty with yourself. For there you will find a friend, the living Lord Jesus himself, who will startle and surprise you with his gentle goodness as you leave Self behind, in repentance, and bank on him afresh, in faith," (Deeper, 43, 49).