For in Jesus Christ neither circumcision availeth any thing, nor uncircumcision; but faith which worketh by love.
Note 12 at Ga 5:6: We might add that no other work of righteousness avails anything either, as far as being justified in the sight of God goes. The truth that Paul was presenting was not about circumcision. Circumcision is no longer an issue. Paul so conclusively disproved that circumcision was essential for salvation that nobody argues that point today. However, the same legalistic thinking that Paul countered in these verses lives on today in the doctrine of water baptism (see note 9 at Mr 16:16), church membership, and other acts of holiness that some preach are necessary for salvation.
Paul was simply using circumcision as an example of an act of holiness that the people of his day maintained was necessary for salvation. His point was that faith alone in the love of God, as expressed through Jesus, is the only thing that God demands for justification. To substitute some other act in the place of circumcision, and then proceed as the Galatians had done, is to miss the whole message that Paul was presenting.
Note 13 at Ga 5:6: Paul was saying that faith alone in what Jesus has already done is the only thing that can procure salvation for us. It is true that saving faith is never alone (see note 55 at Mt 7:21) and can be distinguished from all imitations through examining the actions it produces. The actions of faith (see note 4 at Ro 9:32), however, are not the cause but rather the effect. Faith in God's grace is all that's needed (Eph 2:8).
Note 14 at Ga 5:6: There are two ways of looking at the phrase "faith which worketh by love." One way is to say that true, saving faith always expresses itself through love. That is certainly true. A God-kind of faith will always have actions that conform to the commands of God's Word. This is the way the New International Version translated this verse: "The only thing that counts is faith expressing itself through love."
It is also accurate to say that love produces faith or is what makes faith work. We naturally trust those who we know love us. A revelation of God's unconditional love for us will make faith naturally abound in us. Anyone who is struggling with faith has a deficiency in understanding how much God loves them.