In his book, Lectures to My Students, Spurgeon listed four signs to determine whether one is called to the ministry:
1. An intense, all-absorbing desire for the work.
2. Aptness to teach and some measure of the other qualities needful for a public instructor.
3. He must see a measure of conversion-work going on under his efforts.
4. His preaching should be acceptable to the people of God.
Of course, there is no higher calling than to serve God with our gifts and abilities. Question: does the Bible teach such a thing as having a "calling"?