Answer
Vocational ministry is traditionally understood as a career in which someone is paid for working full-time in a Christian organizational setting. Pastors, missionaries, and full-time evangelists are examples of people involved in vocational ministry.
The Latin word from which we get vocation is vocātiō, which means “calling.” In Christian vernacular, vocation refers to God’s call on someone’s life to something he is particularly gifted in or drawn to. One’s vocation may differ from one’s occupation, or job, although the two terms are often interchangeable today. The apostle Paul’s spiritual vocation was that of missionary to the Gentiles (see Colossians 1:1), but his occupation—what he did to provide for himself and his ministry financially—was that of tentmaker (see Acts 18:2–4).
The word ministry means “service.” In a Christian context, ministry involves serving God and others the way Jesus did, as He is our example (see Matthew 20:28 and John 13:13–15). While pastors make their living doing “ministry,” God calls us all to minister in some capacity. Colossians 3:23–24 instructs, “Whatever you do, work at it with all your heart, as working for the Lord, not for human masters, since you know that you will receive an inheritance from the Lord as a reward. It is the Lord Christ you are serving.” Whether it’s a vocation or an occupation, we can work at it with an attitude of serving God.
Vocational ministry is doing what God’s called one to do for the service of Him and others. For some, their vocation also becomes their occupation, as they get paid to do it (see 1 Timothy 5:17–18 and 1 Corinthians 9:7–11). For others, vocational ministry might be something they do in addition to another job that provides their income.