I am so sorry if any of these concepts appear confusing, as I find it difficult to simply grasp it myself, let alone explain it well. Feel free to comment any questions, and I will try to explain better!
I fell apart today because of the same question which has been haunting me for my entire life, “Am I useless to God because of my iniquity, my sin?” The answer is simply,” No.”
Matthew 5:48 commands us to be perfect like our Father. However, one translation for “perfect” is actually “mature.”
Because our sins are covered by the blood of Jesus, God isn’t trying to make us perfect, as in sinless. He is aware of our state. He works and sanctifies us to make us mature.
Colossians 1:9-10 suggests spiritual maturity is knowing and understanding God’s will. God’s will was set so we could do the good works created in advancement for us to do (Ephesians 2:10) and understand, grasp, the love of Christ, as was Paul’s prayer in Ephesians 3:18.
Therefore, I can conclude that, perhaps, God’s main purpose is to grow us to maturity in our understanding of God’s love because “perfect love casts out fear” (1 John 4:18).