Good answers.
This is how I break it out:
"For in Christ Jesus neither circumcision nor uncircumcision has any value (in obtaining a declaration of right standing with God).
The only thing that counts (towards a declaration of righteousness) is faith...
(faith that can be seen) expressing itself through love." (Galatians 5:6 NIV parenthesis mine)
The revelation of truth that was made known to man with the coming of Christ was the truth that man is reconciled to God by faith in the forgiveness of God, not by doing righteous things to somehow make up for sin, or earn salvation.
Paul is saying the only thing that counts towards being justified (made righteous) in God's sight is faith--faith and trust in the blood of Christ to remove sin guilt and bring us into peace with God. Righteous works of the law, particularly circumcision, have no power to justify a person. They can only show a person to have the righteousness of God--a righteousness that can only come by faith in the Promised Son, Jesus Christ.
And Paul is also pointing out what James says in his letter. The faith that justifies is the faith that loves. Many, many people, apparently even in the days of the Apostles, succumb to the belief that having faith and being saved is somehow just a mental knowledge that God and the gospel are real. But the scriptures teach that to have a faith that does not manifest itself in a changed nature and a new mindset about obedience to God via the fruit of the Spirit is a faith that can not save. He plainly says the faith that justifies is the faith that manifests the fruit of the Spirit, love. But we live in a time in the church when the belief that faith does not have to 'work' to be able to save, because salvation is so utterly by grace alone, is rampant. It's a sad and tragic misunderstanding of Paul's 'righteousness (by faith) apart from works' teaching in Romans.