Part of faith is taking action. If you feel prompted by God to sing in the church choir or play an instrument on the worship team, open your schedule and start practicing!
If you feel God calling you to the mission field, surrender and commit to follow. In addition, contact some mission organizations, talk to the missions leader in your church, go on a short-term mission trip, or take some other kind of action that will help you prepare.
You get the point. Surrender to the leading of the Lord, but also take action. God will do God's part, but we need to do our part. God called Moses, but Moses had to head back to Egypt and stand before Pharaoh.