Faith Alone or Grace Alone?
Those are TWO different theologies.
It is not a question of faith or grace, but of both; they are not two different theologies, but work together as one. Itwin pointed out to you in post number 2 that faith alone is not the only “sola”; these do not stand alone, but together help define reformed theology.
Here’s an excerpt from the Solid Declaration of the Formula of Concord:
9] Concerning the righteousness of faith before God we believe, teach, and confess unanimously, in accordance with the comprehensive summary of our faith and confession presented above, that poor sinful man is justified before God, that is, absolved and declared free and exempt from all his sins, and from the sentence of well-deserved condemnation, and adopted into sonship and heirship of eternal life, without any merit or worth of our own, also without any preceding, present, or any subsequent works, out of pure grace, because of the sole merit, complete obedience, bitter suffering, death, and resurrection of our Lord Christ alone, whose obedience is reckoned to us for righteousness.
10] These treasures are offered us by the Holy Ghost in the promise of the holy Gospel; and faith alone is the only means by which we lay hold upon, accept, and apply, and appropriate them to ourselves. 11] This faith is a gift of God, by which we truly learn to know Christ, our Redeemer, in the Word of the Gospel, and trust in Him, that for the sake of His obedience alone we have the forgiveness of sins by grace, are regarded as godly and righteous by God the father, and are eternally saved.
bookofconcord.org/sd-righteousness.php#para12
Here you see that sinful man is justified before God by grace alone, without any merit or worth of his own. This justification by grace is extended to sinful man because of Christ alone; it is by His work, His obedience, His suffering, death, and resurrection, that we can be justified, not by any merit or worth of our own. Here we also see that faith alone is the means by which we accept and apply to ourselves the benefits gained for us by Christ, and even this faith is not something meritorious in us, but is itself a gift of God. So just in the doctrine of justification we see sola gratia, sola Christus, and sola fide, not three different theologies, but one theology, rightly understood.
Another point brought up in this thread is that salvation is more than just justification. I provided a link to a systematic theology by Boyce that has chapters that go into some detail about some of the different aspects of salvation, but here is an excerpt from a short article that might help.
Of the various descriptions of salvation in Reformed theology, ordo salutis, order of salvation, is the earliest. The purpose of the ordo is to list the events in the life of every saved person that join him to Christ. Typically, the list of events looks like this: effectual calling, regeneration, faith, repentance, justification, adoption, sanctification, perseverance, glorification. In effectual calling, God summons the elect person out of sin and into union with Christ. This gives him a new spiritual birth, a new heart, or regeneration. That regenerate heart enables the redeemed person to believe or trust in Christ (faith) and to repent of sin. Repentance is the opposite side of the coin from faith. Faith is turning to Christ, repentance turning away from sin, and you can’t do the one without doing the other. Justification, God’s imputation to us of Christ’s righteousness, is by faith, so it follows faith and repentance in the ordo. Those whom God justifies, he adopts into his family. Then there is sanctification, which means both that we are separated from the sphere of the world into the sphere of God’s kingdom (“definitive sanctification”), and also that we become progressively more and more holy by the work of the Spirit within us (“progressive sanctification”). This new life within enables us to persevere in faith and love, until the consummation of all things when our glorification is complete.
frame-poythress.org/salvation-and-theological-pedagogy/#
The author of that article goes on to say that even the ordo is not the totality of the doctrine of salvation, but is a useful teaching tool–he said that when he studied the ordo salutis with John Murray (author of Redemption Accomplished and Applied), “all sorts of lights went on, all sorts of strands in Scripture got connected for me.” When I attended a Baptist church, the pastor there included Murray’s book as one of those that he said should be in every Christian home. I should probably pull it off the shelf and re-read it myself.