Does faith save us?

In what way does faith save us? Here Ebenezer Erskine gives the best summary I have found of saving faith in the object and person of Christ. Faith as obedience to the law but not work. Faith as living in me but not self generated:

Does faith save us ? Yes it does: but then it turns the glory of salvation over upon the author thereof, saying, “Our God is the God of salvation.” Does the just man live by faith? Yes: but then faith steps in with “It is not I:” Gal. ii.20 . “I live; yet not I, but Christ liveth in me.” Does faith justify ? Yes, it dose: but then its language is, “Surely in the Lord have I righteousness, in him will I be justified, and in him alone will I glory.” Can faith do everything ? Yes, but it is by leaning on the arm of omnipotency. “I can do all things through Christ which strengtheneth me.” Thus, I say, faith arrogates [attributes to another] and claims nothing to itself, but gives unto the Lord the glory due unto his name. And so zealous is faith to have God alone exalted, particularly the freedom of his grace in the justification and salvation of a sinner, that, though believing be the highest and greatest act of obedience that a person can yield unto the moral law, yet that boasting may be for ever excluded, it excludes and shuts out itself from the rank and category of works, or acts of obedience, Rom. iv. 5. “To him that worketh not, but believeth in him that justifieth the ungodly, his faith (objectively considered) is counted for righteousness.” It is the peculiar excellency of faith, that it sinks its own act, that its blessed object, CHRIST, may be “all in all; it rejoices in Christ Jesus, and triumphs always in him.” And though, as I was saying, it be the poorest, lowest, and most beggarly of all the other graces; yet it is a grace that prides itself in the Lord Jesus, and by his blood enters with boldness into the holiest.