David makes an incisive statement in the eighteenth Psalm, thirty-second verse. He says "it is God that...maketh my way perfect". (emphasis mine)
I'll pause to let that sink in.
Turn over with me to Paul's New Testament letter to the Colossians (3:14): "And above all these things (mercy, kindness, humility, gentleness, patience, endurance, forgiveness, from the preceding verses) put on charity, which is the bond of perfectness." (emphasis mine)
Everyone wants to be perfect. Perfect in some way. And I'd venture to say that that's the way God designed us to be. To strive for excellence. "Strive for the mastery" as Paul put it (1 Corinthians 9:25). Jesus says to "be ye perfect, even as your Father in Heaven is perfect" (Matthew 5:48). Is Jesus going to ask us something that He knows we can't hope to fulfill? Before we ask that question, as I think that is the unspoken thought in many people who read that verse and compare it with their very imperfect behavior (myself included), I think we need to break down the components regarding us, God and the natural order of things.
We have the desire to please God, that's a given. Literally given to us by God. This is one of the main proofs that shows we're born again by His Spirit: "The natural man (and woman) receiveth not the things of the Spirit of God: for they are foolishness unto [them]: neither can [they] know them, because they are spiritually discerned." (1 Corinthians 2:14). So if you're struggling with sin and downtime, take heart. You wouldn't even care if you were unsaved. But moving forward, as we all know, we meet in ourselves desires that run counter and contradictory to God's order. Forgive me for sounding lenient here, but please don't beat yourself up for making mistakes that, without God's help, are inevitable. God doesn't condemn me. I can do that for myself thank you very much. Sin and imperfection begin with our turning away from God. The sin is the separation. The outward mistakes that we make are symptomatic of a greater inward need. If we could control every single bodily function, then that would make us God and where would God be then? Here's an answer for you: "but if ye through the Spirit do mortify (put to death) the deeds of the body, ye shall live." (Romans 8:13) The separation I referred to a moment ago is what Jesus came to heal. And He did. He stands in that gap and helps people across. As such, we are now "[seated] together in Heavenly places in Christ Jesus" (Ephesians 2:6). In John's gospel, chapter thirteen, Jesus says "He (and she) that is washed needeth not save (except) to wash [their] feet, but is clean every whit" (verse 10). What Jesus is saying here is that, because you're born again, you're clean—you're perfect in His sight. However, we might stray off the path into sin and get our feet muddy. This is inevitable on this earth. Ask for forgiveness, clean your feet and move on. Know that you did nothing to obtain, to appropriate this state for yourself. Jesus is the one who washes both us (see John 13:8) and our feet (13:5). He cares more about it than do we. "It is God that maketh my way perfect..." He loves us before we're perfect and, well, He loves us. That's all there is too it. And the humility of mind and heart that accepts this reality—as reality—and then lives in accordance with it, is perfect enough for God. With the worship and praise that should then come naturally.
Now, moving on, consider this statement of James: "but let patience have her perfect work, that ye may be perfect and entire, wanting nothing" (James 1:4, emphasis mine). When it says "wanting nothing" in the King James, it means needing nothing. And that refers to getting our needs met by God alone and not through our own effort. Philippians 4:19 "But my God shall supply all your need according to His riches in glory by Christ Jesus" This is where the hard work of faith and discipline come in. And as we are saved (if I may) and desire to please God, we're going to do this with His help.