God has acted in Christ for human redemption, and that is a gift of a gracious God. A right relationship with God is by faith, not seeking God’s favor by good works.
This verse was one of the most important utterances A Christian missionary who once persecuted the church made in his Letter to the Romans, both for his time and for later history. One cannot achieve a right relationship with God by keeping regulations, even those prescribed by the law in the Old Testament. A right relationship exists where a person trusts in the promises of God set forth in the death and resurrection of God’s Son–that is, by faith. Martin Luther actually altered the verse in his German translation of the New Testament of 1522 by inserting the German adverb allein (“alone”), so that the verse read (in English translation): “For we hold that a person is justified by faith alone apart from works prescribed by the law.” To change the text in that way would not normally be permitted today (although translators do in fact put in words that have no textual basis, strictly speaking, such as at Romans 5:9 where the textual basis says simply “wrath” but modern translations [for example, NRSV, RSV, NIV] render the Greek as “wrath of God”). Every translation is an interpretation, and it can be argued that Luther caught the sense of what had been written.