Is anyone among you sick? Then he must call for the elders of the church and they are to pray over him, anointing him with oil in the name of the Lord; and the prayer offered in faith will restore the one who is sick, and the Lord will raise him up, and if he has committed sins, they will be forgiven him. Therefore, confess your sins to one another, and pray for one another so that you may be healed. The effective prayer of a righteous man can accomplish much. 
(James 5:14)

Altar Ministers stand in the gap to assist the Pastor (or preacher) at the altar rails to pray during ministry time with those who have responded to the call from the pulpit or come up for prayer.