Is anyone among you sick? He should summon the presbyters (priests) of the church, and they should pray over him and anoint [him] with oil in the name of the Lord and the prayer of faith will save the sick person, and the Lord will raise him up. If he has committed any sins, he will be forgiven. Therefore, confess your sins to one another and pray for one another, that you may be healed. The fervent prayer of a righteous person is very powerful. James 5:14-16
Sounds like he is saying that the sins of the sick are forgiven in the sacrament of anointing. He specifies that the priests must be called. They obviously had a power that ordinary Christians did not: the power to forgive sins. Otherwise, why not just ask an ordinary, fellow Christian to pray over the sick as is the case in numerous other passages.
Oh, and check out 2 Corinthians 5: 17-20
So whoever is in Christ is a new creation: the old things have passed away; behold, new things have come. And all this is from God, who has reconciled us to himself through Christ and given us the ministry of reconciliation, namely, God was reconciling the world to himself in Christ, not counting their trespasses against them and entrusting to us the message of reconciliation. So **we are ambasadors **for Christ, as if God were appealing through us. We implore you on behalf of Christ, be reconciled to God.
Sounds pretty clear to me. St. Paul is explaining how the Apostles are ambassadors of Christ’s work of reconciliation and that they share in the ministry of Christ and forgive sins in His name!!