John Calvin: Faith does not justify but insofar as it receives and rests solely upon Christ

John Calvin explains that God alone justifies and that faith is a vessel that comes empty to receive and rest upon Christ and His righteousness alone:

I willingly concede Osiander's objection that faith of itself does not possess the power of justifying, but only in so far as it receives Christ. For if faith justified of itself or through some intrinsic power, so to speak, as it is always weak and imperfect it would effect this only in part; thus the righteousness that conferred a fragment of salvation upon us would be defective. Now we imagine no such thing, but we say that, properly speaking, God alone justifies; then we transfer this same function to Christ because he was given to us for righteousness. We compare faith to a kind of vessel; for unless we come empty and with the mouth of our soul open to seek Christ's grace, we are not capable of receiving Christ. From this it is to be inferred that, in teaching that before his righteousness is received Christ is received in faith, we do not take the power of justifying away from Christ. (John Calvin, Institutes, III:11:7)