Matthew 25:28-30
"…28'Therefore take away the talent from him, and give it to the one who has the ten talents.'
29"For to everyone who has, more shall be given, and he will have an abundance; but from the one who does not have, even what he does have shall be taken away.
30"Throw out the worthless slave into the outer darkness; in that place there will be weeping and gnashing of teeth."
There is a regression that occurs when a believer begins to neglect the things of the Lord in favor of friendship with the world. So many believers are disobeying God in major ways, choosing to believe God winks at their personal choices, or twisting Scripture to enjoy their own desires.
When we see that we or someone we know are beginning to accept things they never would have in the past, or begins to fight against the truth when corrected, then we will be able to observe a reversal in the spiritual walk.
This is also the reason we become confused, people who appear to be on fire for God, after many years of capitulating to the whims and desires of people around them, begin to falter in their walk and seem to even give up all desire for the things of the Lord, having a psudo-Christianity that has no power.
Matthew 13:12 "For whoever has, to him shall be given, and he shall have more abundance. But whoever does not have, from him shall be taken away even that which he has"
Do not think for one moment that we can neglect the principles of God, ignoring them, while expecting to retain the knowledge we have. Our life will go down the path that is most traveled, the easiest for us. As we continually fill our souls with the Word, obeying what we know, God will heap more wisdom upon us. However if we neglect Him, His principles, remaining disobedient, we will regress, perhaps so much so that we barely appear to be Christian anymore.
For those who find themselves feeling flat in their walk, having lost joy and excitement about the Lord, it would be prudent to get back on your knees confessing your apathy, asking the Lord to revive your spirit to begin to walk uprightly again.
If there is no confession, no sorrow over this condition of regression, then there can be no healing, things will continue the downward slide to complete apostasy, then is when we have to ask ourselves if we were ever born again.
Those who are born again should be sensing the prodding of the Holy Spirit until there is that confession.
1 John 1:9 "9 If we confess our sins, He is faithful and righteous to forgive us our sins and to cleanse us from all unrighteousness."