Every command of God is built upon a promise from God. Every divine call to action (obedience) is, at the same time, a divine summons to trust in God's promises (faith). The promises of God are commands in disguise, and vice versa. God commands what he commands because he promises. After the Exodus, God promised Israel that it would rain bread from heaven every day except the Sabbath. God therefore commanded Israel not to gather more than their daily ration, except on Friday. God's promise was inextricably linked with a prohibition. Conversely, trust in God's promise would mean obedience to his commands.
Disbelief always shows up as an act of disobedience, since every promise carries with it a command. Every time we disobey God, it is because we are not trusting his promises.
