Maybe you've heard of the expression "Two steps forward, one step backward." The road to maturity isn't all uphill as if we're always on a spiritual high. Satan likes to nip our progress in the bud and catch us on spiritual highs when we are most vulnerable and can be caught off-guard. Recall that he tempted Jesus right after his baptism for 40 days in the wilderness when Jesus couldn't have been more vulnerable. I like the slogan "PBPGIFWMY," which means, "Please be patient; God isn't finished with me yet!"
The famous heretic British monk Pelagius thought that Adam's sin only affected him and we have the ability to be sinless and perfect, which can be referred to as "perfectionism." Today Methodists also believe that a believer can reach a level of maturity where he doesn't sin any more willfully. This is a false doctrine and we will not be perfect until we reach the terminus of the golden chain of redemption, "glorification" per Rom. 8:30. In heaven, we will be free but unable to sin, because we won't have the old sin nature anymore, but be sinless and holy. Sin cannot dwell in God's presence because He is holy. Paul himself claimed that he hadn't yet "arrived" or laid hold of it yet; how much more are we do not think that we have to room for improvement.
We are never to get cocky or self-righteous and look down on our fellow believers; for with God, there is no respect of; persons. Before the Lord, we are all "positionally" holy and righteous regardless of our experiential state. Our status is settled in Christ regardless. Isa. 65:5 warns against a so-called "holier-than-thou" attitude. We are all "one in Christ" and there is neither male nor female, Jew nor Gentile, Greek nor barbarian, slave nor free.
In heaven, we will all be equally holy and in a glorified state like Christ but may have different responsibilities or rewards earned during this life, which is the staging area for eternity. You might call it a dress rehearsal. We should be like Paul, who in his swan song declared, "I have fought the good fight, I have finished the course, I have kept the faith," (2 Tim. 4:7). He who is faithful in little is faithful in much--this is encouraging to the little guy who seems insignificant or unimportant. Soli Deo Gloria!