In an article about sanctification for The Gospel Coalition, Wendy Alsup writes, “When you feel ‘stuck,’ when you feel like you are continually rehearsing the same struggles, remember this: sanctification is not an endless, repetitive circle. It is a growing spiral in which each round penetrates more deeply into our identity as fallen, but redeemed, image-bearers of God. Spiritual growth can be a long, slow process—with one step backward for every two steps forward—but as you trust in Christ, God will complete the work he has begun in you (Phil. 1:6). Remember: your spiral is not a circle!” (Article source: https://www.thegospelcoalition.org/article/the-sanctification-spiral)
Sanctification is not a linear line that keeps going up no matter what. We may struggle and fall and the Holy Spirit will continue to work in us to make us more like Christ.