A wise man once told me that your marriage is always either getting better or worse, depending on what you are doing for it on an ongoing basis.
I believe it is the same way with our relationships with God.
It explains a lot, too. Unless we bring this dynamic phenomenon into the picture, we find ourselves at a loss to explain well-known shifts in behavior that seem out of left field. How could Solomon, who was the wisest man in the world, go off into sin? How could David slip away from his place of abiding into a horrendously costly foray with Uriah's wife? How do these things happen?
Each of us has heard of godly preachers who have "fallen from grace," as they say. They led wonderful churches or ministries, and next thing you know a public scandal explodes. When this happens, I personally do not see any reason why we should immediately conclude that the man was a scoundrel all along, much less that he was never really a Christian.
No, I think it gets back to what that person once told me about marriages: The state of something is always getting either better or worse.
Nothing stands still. Life is but a series of moments, each containing a choice. Each choice is either to obey the present impulse of the Spirit or to disobey. Each choice is either to act in love or in selfishness, in faith or in unbelief.
For the most part, no one but you sees the tiny moment-by-moment decisions you make. You may disobey the little promptings of God for years or decades before they ever reach critical mass to "out" you in one great flamboyant fiasco. By the time everybody else sees that you have sinned against God, you have been doing it consistently for ages.
Oh, for a friend who will catch me early, who knows me well enough to see the telltale signs of my nearly invisible slippages!
"Brothers, if anyone is caught in any transgression, you who are spiritual should restore him in a spirit of gentleness" (Galatians 6:1).
"My brothers, if anyone among you wanders from the truth, and someone brings him back, let him know that whoever brings back a sinner from his wandering will save his soul from death and will cover a multitude of sins" (James 5:19-20).