Moo: “The Bible pictures all human beings as defendants in a courtroom: a courtroom in which God is the judge and our sins constitute the evidence against us. The judge weighs the evidence and finds every single one of us guilty of sin and announces that we, therefore, must be condemned. The marvellous news of justification is that God has himself provided for us the means of escaping that condemnation: by responding to his gracious initiative in faith, we become joined with Christ, who died for us and was raised for us. We become joined to Christ, who takes on himself the penalty for our sin and covers us with the ‘righteousness’ that we need to reverse the verdict of condemnation and receive the verdict of ‘justified’, ‘right’ with God. And because we have been joined to Christ, the holy one, and have in that union received the gift of God’s powerful holy Spirit, we, who have been justified, also find our lives transformed so that we love God and neighbour.”
“Paul’s teaching on justification in Galatians strongly endorses the traditional Reformation emphasis on justification by faith alone. In contrast to some recent reconfigurations of this doctrine, the Reformers did not mean by this teaching that a person gains only initial entrance into the state of salvation by faith alone—the ultimate verdict being based on faith plus works. They intended to assert that the eschatological gift of justification, at whatever “time” or in however many stages it might be manifested, came by faith alone.
Paul seems to be saying just this in Galatians. Faith is the means not only of entering into relationship with God but also of maintaining that relationship and of confirming that relationship on the day of judgment. Of course, it is not faith in itself that has this power; it is because faith connects the believer to Christ, in whose vindication (see 1 Tim. 3:16) the believer shares.
My brief overview confirms those who find a monergism in Paul’s teaching about salvation that stands in contrast to the synergism of covenant nomism. Justification, not only in its initial phase, but in its totality, is sola fide—and, though it has not been a focus of this study, in light of Galatians 2:21 and 5:4, sola gratia also.”