All who see the individual's life can read it as a letter from God. Paul explained that the Lord is that Spirit that he ministered. We find one of the purposes in undergoing baptism in Jesus' name here. It exposes our hearts to Jesus' glory. We must expose the heart to the Spirit that the Spirit might write upon it.
Baptism removes the old man, or the veil, from off the heart.
This causes the heart to be open to Jesus' Spirit. We discover that baptism is a means of applying the Lordship of Jesus Christ over one's life. That is what baptism accomplishes. It is an act which shows the surrender of independence. Baptism is an answer to the Lord from a good conscience.