Faith is nothing but the instrument of our salvation. Nowhere in Scripture will you find that we are justified because of our faith; nowhere in Scripture will you find that we are justified on account of our faith. The Scripture never says that. The Scripture says that we are justified by faith or through faith. Faith is nothing but the instrument or the channel by which this righteousness of God in Christ becomes ours.
It is not faith that saves us. What saves us is the Lord Jesus Christ and His perfect work. It is the death of Christ upon Calvary's cross that saves us. It is His perfect life that saves us. It is His appearing on our behalf in the presence of God that saves us. It is God putting Christ's righteousness to our account that saves us. This is the righteousness that saves; faith is but the channel and the instrument by which His righteousness becomes mine. The righteousness is entirely Christ's. My faith is not my righteousness and I must never define or think of faith as righteousness. Faith is nothing but that which links us to the Lord Jesus Christ and His righteousness.