Here's a conflation of two posts from last year on the question of singleness of heart.
Living without integrity is a shameful thing - this is why we tie ourselves in knots to rationalize our bad behavior, so that we can convince ourselves (at least) that we have personal integrity - though our friends and family generally know better.
What is integrity? It is integration as opposed to disintegration, living as a man or woman whose actions and beliefs are integrated, made one. When the things we do don't match the things we profess, we have no integrity. We become hypocrites.
Integrity, then, is nothing other than living in accord with the Truth.
Sin, by contrast, is Living the Lie. When we sin, we deny the built in borders of reality (such as the nature of love and sex) and assert in its place our own Unrealities (such as sodomy, contraception and adultery), turning from the truth and serving the Lie, turning from "the way, the truth and the life" (John 14:6) to the wayward, the false and the death.
For we are torn. We are double-minded and thus unstable in all our ways (James 1:8). St. Paul says it best ...
For I have the desire to do what is good, but I cannot carry it out. For I do not do the good I want to do, but the evil I do not want to do—this I keep on doing. (Rom. 7:18-19)
... which leads him to conclude ...
In my inner being I delight in God’s law; but I see another law at work in me, waging war against the law of my mind and making me a prisoner of the law of sin at work within me. (Rom. 7:22-23)
In other words, our hearts are divided. The right ventricle is at war with the left. Inside our deepest selves is a kind of schizophrenia. We delight in God's law - in what is True, Beautiful and Good - but we also reject it and trample on it.
Let us pray, then, for Singleness of Heart, for Undivided Hearts, for hearts made pure, true hearts of flesh, not false hearts of stone.
Lord, make us of one mind and of one heart - may we not be double-minded, double-hearted, double-tongued (speaking out of both sides of our mouth and lying), but integrated - fully serving You, the God of Truth. May our hearts be molded unto Mary's, and thereby molded unto Yours.
- Watch over your heart with all diligence, For from it flow the springs of life. - Prov. 4:23
- Draw near to God, and he will draw near to you. Cleanse your hands, you sinners, and purify your hearts, you double-minded. - James 4:8
- And they, continuing daily with one accord in the temple, and breaking bread from house to house, did eat their meat with gladness and singleness of heart. - Acts 2:46
- I will give them an undivided heart and put a new spirit in them; I will remove from them their heart of stone and give them a heart of flesh. - Ez. 11:19