With a couple of plain illustrations in one of his sermons (#1126), Charles Spurgeon explains how faith does not merit or earn salvation, but the instrument which apprends God’s gracious provision of pardon:
Faith saves us just as the mouth saves from hunger. If we be hungry, bread is the real cure for hunger, but still it would be right to say that eating removes hunger, seeing that the bread itself could not benefit us, unless the mouth should eat it. Faith is the soul’s mouth, whereby the hunger of the heart is removed. Christ also is the brazen serpent lifted up; all the healing virtue is in him; yet no healing virtue comes out of the brazen serpent to any who will not look; so that the looking is rightly considered to be the act which saves. True, in the deepest sense it is Christ uplifted who saves, to him be all the glory; but without looking to him ye cannot be saved, so that “There is life in a look,” as well as life in the Savior to whom you look. Nothing is yours until you appropriate it.”
…Faith is the hand of the soul. Stretched out, it lays hold of the salvation of Christ, and so by faith we are saved. “Thy faith hath saved thee.” I need not dwell longer on that point. It is selfevident from the text that faith is the great means of salvation.
Thanks Mr Spurgeon!