Faith is therefore not a generic optimism: a positive outlook on life. It is not even a general trust in God and his promises to care for us. Saving faith is not merely “believing God for the big things.” Saving faith is very specific: clinging to God’s saving mercy in Jesus Christ as he is given to us in the gospel. Faith produces the fruit of love and good works, but in the act of justification it simply hears and receives. There is no virtue in faith itself that justifies. Even the weakest faith clings to a strong Savior.
Horton, Michael; The Gospel Driven Life: Being Good News People in a Bad News World; Baker Books; Grand Rapids, MI; Copyright 2009; page 122