Grace is God moving in us and through us. It is the love of God which is shed abroad in our hearts by the Holy Ghost. Faith gives us access to God's grace. Faith is a supernatural trust that comes from God--it is God's faith in us, and it comes when God speaks to us, whether through His creation, through His Bible, through His saints, or in a still small voice from within telling us, "This is the way, walk ye in it." (some caveats about hearing God's Voice)