In the case of those among the brethren who are 'astheneo', weak, feeble, sick, they are shown how to seek healing from the Lord.
This could mean sending for the elders to come and pray, the sick one being unable to go to the elders. In this, faith is active. Or the sick one comes to the meeting and requests
prayer of the elders, so through a step of faith, what is implied is that the sick one is the first in taking the initiative in an act of faith in seeking divine healing.
Elders must concentrate prayer over the sick one. "Over him" means focussed prayer on the needy one, and the specific need itself. Along with prayer, the elders are to anoint the
sick one with oil. It is a symbol of the Holy Spirit who is shown in the "gifts of healings" (1 Corinthians 12:9,28,30 ). Just as bread and wine are symbols of the body and
blood of Jesus Christ (1 Corinthians 11:24-25 ), so the oil symbolises the presence of the Holy Spirit in power to glorify Jesus. In healing works the Holy Spirit does glorify
Jesus in declaration, and He also does in demonstration (John 16:14-15; 1 Corinthians 2:4-5 ) in response to prayer for, and anointing of the sick "in the name of the
Lord" (James 5:14 ).
9.3. PRAY IN TIMES OF SICKNESS (James 5:14-18)
9.3.1. FAITH EXPRESSED ON THE PART OF THE SUFFERER (James 5:14)
James 5:14 "Is any sick among you? let him call for the elders of
the church; ..."
9.3.2. ELDERS RESPOND IN SPECIFIC ACTS OF FAITH (James 5:14)
James 5:14 "... and let them pray over him, anointing him with oil in
the name of the Lord:"

It is used in recognition of the Lord being present in the midst:
Matthew 18:20 "For where two or three are gathered together in my
name, there am I in the midst of them."

It is acknowledgment that all service and actions of faith are to be done in His name:
Colossians 3:17 "And whatever you do in word or deed, do all in
the name of the Lord Jesus, giving thanks to God the Father through Him."

It is that the divine source of healing may be clearly known (Acts 3:6 ):
Acts 4:10 "let it be known to you all, and to all the people of
Israel, that by the name of Jesus Christ of Nazareth, whom you crucified, whom God raised from the dead, by Him this man stands here before you
whole."

It is using the name of Jesus, for to Him all authority is given:
Matthew 28:18 "And Jesus came and spoke to them, saying, "All
authority has been given to Me in heaven and on earth."

It is using the name which is above every name:
Philippians 2:9 "Therefore God also has highly exalted Him and
given Him the name which is above every name,"

It is the name to which every knee shall bow, including demons and sickness:
Philippians 2:10 "That at the name of Jesus every knee should bow,
of things in heaven, and things in earth, and things under the earth;"

It is faith action that confesses Jesus as Lord:
Philippians 2:11 "And that every tongue should confess that Jesus
Christ is Lord, to the glory of God the Father."