In all the verses where you see that God gives credence to one's faith, their faith is an "evidence" of what He has already done spiritually.
Ukuhlola ukuthi wenza ukulunga kukho konke okwenzayo yini, nokuthi zonke izenzo zakho ziyabonwa yini uNkulunkulu, kuyizimiso zokuziphatha zalabo abakholwa kuNkulunkulu.