If we being human beings, with a sinful nature!
Yet believe in the work Christ done on the cross
Taking the sins of the world by dying on the cross!
How can the spirit of God dwell within us?
Yet we still struggle with in.
yes difficult to understand those besetting sins. It is hard to divorce those physical things from our spiritual nature.
We are the sum of our experiences and there will be things that we have to learn to let go of and come to repentance. however, when we come to Christ and declare he is Lord, we undergo a spiritual second birth and as we grow in the knowledge and Love of God we come to a point of receiving the infilling of the Holy Spirit, this confers on us certain gifts we can use in ministry to others. So we have to look to the renewing of our mind, which is not our spirit. The strongholds that have been built up in us have to be taken over as the scripture says casting down every imagination and taking it captive. We must become open to hearing from God
Christains must understand they will never be perfect this side of heaven, we are being perfected and the Grace of God is sufficient. We have an enemy who will keep reminding us of past transgressions but we have to keep reminding him that we have repented and are forgiven and that repented sin is covered by the blood of Jesus, no longer remembered. If we go back we must walk the path of repentance again.
Christians were never told they would not struggle, in fact Paul tells us we are in a war, but it is not a war we fight alone, however Christians are told that by their belief they are born to eternal life. Remember it is a finished work and we cannot add to it.