Living out the life that God has called us to live by faith is impossible without us surrendering to the Holy Spirit in us to strengthen and provide for us the grace that is needed to do so. The Spirit gives life but the flesh profits nothing. In other words, the flesh has nothing to offer us in our efforts to walk in faith. Our flesh and the spirit are in opposition to one another so that we are unable to do what we desire to do for God. 
Our salvation required the Holy Spirit to reveal the sin in our lives as well as the grace that God was offering to us for that salvation. Our sanctification requires the Holy Spirit to continue to reveal and provide all that we need to grow in our faith and produce fruit to the glory of God.
The evidence of the Holy Spirit working in our lives is seen by our increasing desire for Christ and His love to dominate every area of our lives. 
Are you sealed with the Holy Spirit? Is there evidence of His fruit?