When you declare Jesus Christ as Lord:
1. He will use you to build His Church. (18)
We are the stones that make up the building of His Church.
2. He will use you to do His will. (17)
We need defensive armor to ward off the attacks of the enemy while we are fighting, but we are to be on the offensive against the enemy.
3. He will use you to open doors. (19)
It is not our own agenda that we are opening doors to, it is His kingdom.
We can't water down the gospel or change the truth of the Bible just to open up doors for more people to come to Christ.
Your declaration of faith is a declaration of dependence.