We cannot say why your church does what it does. Perhaps you could ask one of your spiritual leaders. The New Testament makes two references to oil in connection with healing the sick. Mark 6:13 says, 'And they cast out many demons, and anointed with oil many who were sick, and healed them.' James 5:14 says, 'Is anyone among you sick? Let him call for the elders of the church, and let them pray over him, anointing him with oil in the name of the Lord.' These are the only verses we have to go on concerning anointing with oil.