In Peter's second letter, he makes an important statement about continuous growth: "If these characteristics are in you and continuously increasing, you will become effective and fruitful in your experiential knowledge of Christ" (2Pet.1:8, paraphrased).
Forward movement in our spiritual journey is crucial to our experience of God's work in us and our joy in being enriched by Him. In fact, movement toward a deeper relationship with God and toward more of His activity in our life is the basic definition of being in God's will. How far along the journey we are has little to do with whether we are in relationship with Him. We do not have to be perfect to be in God's will; we only need to be in motion, growing and becoming more like Him. That means we can all be in God's will, no matter how messed up we are!
That's the good news Jesus announced on the mountainside: "Blessed are all you who are spiritually impoverished, because you get to live within the realm of God's will" (Mt.5, paraphrased).
Of course, how to keep growing is another matter — that's what Christian Formation is all about. But continuous, life-long growth is not only possible, it is God's intention for us. When He says, "My ways are higher than your ways" (Isa.55) He is letting us know that there is no limit to how much we can grow. When He gives us His Spirit to restore and mentor us, He is giving us the means to grow. And once we learn how to participate with Him in this journey, it does not take long to discover not only that each step is filled with joy, but that we have an infinite number of steps ahead of us!
I can think of no better reason for wanting to join Him and to keep moving forward!