I heard a speaker recently talk about ministry as a fusion of calling and gifting. Both the call and the gifting are given by God to those he chooses to minister to his church. And both the calling and the gifting must be operational for ministry to be effective.
The call should be a product of an ever deepening relationship with God. As the name implies, gifting is the ability to do the ministry that one called is to do.
The gifting along with the talents and personality of the one called are given by God to meet the needs of the church.
The danger is that a minister can lose sight of his call and rely almost exclusively on his gifting. A gifted speaker can churn out entertaining and perhaps even helpful sermons without being in touch with the God he claims to serve. In my lifetime, I have seen too many preachers get caught in egregious behavior that was performed while they were continuing in what appeared to be successful ministry. Apparent effectiveness is not necessarily an indication of a deepening relationship with God.
On the flip side, a man can feel called to ministry but not have the gifting, talents and abilities to function in the role he feels called to fill.
This is why it is necessary to have a presbytery or some other governing body to evaluate and qualify those who feel the call to ministry. But it should be understood that when a pastor is ordained, the ordaining group is simply confirming that the gifting is indeed operational in the candidate as he ministers to the body. The gifting must be validated and affirmed by mature believers.
For the minister to be effective, he must acknowledge that both the gifting and calling come from God and the minister is dependent upon God for maintenance of them both. This requires humility.
It does not require the kind of humility that is self deprecating or self defeating. It requires the kind of humility that understands that God could use anyone, but is grateful for the opportunity to be used. Like any other gift, the giver should be thanked for providing the call and gifting to go along with it.
Paul writes about this in Ephesians 4 when he says,
And he gave the apostles, the prophets, the evangelists, the shepherds and teachers, to equip the saints for the work of ministry, for building up the body of Christ, until we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ, so that we may no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine, by human cunning, by craftiness in deceitful schemes.Ephesians 4:11–14 (ESV)
God gives. Man can only receive.