He exposes guilt and the need for forgiveness. This lays the ground work for evangelism. When we share Christ with our friends, we need to trust that God's Spirit is personally confirming the truth of what we say. It may not be apparent to us, and it may be a process of some time, but God is wrestling with fallen people's rebellious hearts. God wants us to know that we are fully acceptable to him.
Assurance is vital for a dynamic Christian life.
When we read the scripture or hear a teaching we find an inner conviction that what we are hearing is true, that it speaks to our lives. We just know that what we are being confronted with is from God. We should ask God to reveal his will for us as we get involved in the Bible. God is actively involved in all of our circumstances. He enables us to make sense out of the seemingly fragmented experiences of life.