Our salvation doesn't depend on our righteousness, but on God's grace. We could never hope for heaven, we could never have our sins forgiven, and we could never have eternal life without God first deciding to give us these things. Grace is what makes Christianity so great.
Any theology that construes salvation as some sort of cooperative effort between God and man is false. Whatever man does in reference to his salvation may be seen as responsive, not causal. Jesus, God's gift, is the sole cause. (p. 105)