Some people consider faith to be a set of beliefs as laid out in confessions and creeds. Are we saved by grace through a set of beliefs and doctrines? Other people consider faith to be membership in a religious organization as in "I'm a member of the Christian faith or Islamic faith." But, are we saved by grace through membership in organized religion? Asked that way, neither of those definitions sound quite right.
Simply stated, faith is trust. Think "leap of faith" or "trust falls." We are saved by grace through trust. God looked with favor on Abraham because Abraham trusted him. God sent his Son so that we would trust him. This is how Peter says it, "Through Jesus you have come to trust God, who raised him from the dead and gave him glory, so that your trust and hope are set on God."
So we don't have to keep up with the law or make all kinds of sacrifices to atone for our sin. All we have to do is trust God. Because God raised Jesus from the dead, we can entrust our life to God knowing that nothing can separate us from his love. When we trust, God forgives and pours the Holy Spirit into our hearts. Now that's amazing grace!
Church will make more sense if people can find there more than a set of beliefs and something deeper than membership in an organization. Trust is something our hearts seemed wired for, but is at the same time very fragile. People are searching for some way to trust again. That way is through Jesus.