Is any sick among you? 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:
Let him call for the elders - not some one, as Romanists interpret it, to justify their extreme unction. The prayers of the elders over the sick would be much the same as though the whole church which they represent should pray (Bengel).
Anointing him with oil. The usage which Christ committed to His apostles was afterward continued with laying on of hands, as a token of the highest faculty of medicine in the Church; as we find in 1 Corinthians 6:2 the Church's highest judicial function. Now that miraculous healing is withdrawn, to use the sign where the reality is wanting, would be unmeaning superstition. Compare other apostolic usages, now discontinued, 1 Corinthians 11:4-15; 1 Corinthians 16:20. 'Let them use oil who can by their prayers obtain recovery for the sick; let those who cannot do this, abstain from the empty sign' (Whittaker). Romish extreme unction is administered to those whose life is despaired of, to heal the soul: James' unction was to heal the body. Cardinal Cajetan ('Commentary') admits that James cannot refer to extreme unction. Oil among the Jews (see Talmud, Jerusalem and Babylon) was used as a curative agent (Luke 10:34). It was also a sign of divine grace. Hence, it was an appropriate sign in miraculous cures.
In the name of the Lord - by whom alone the miracle was performed: men were but the instruments.