God sent Isaac to another city and just like his father, out of fear, he lied saying that Rebekah was his sister. Even after God told him that He would be with him, he was still afraid. Are we ever afraid, even when we know we are in God's will? Do we Trust him enough to obey fully? Do we follow Him or base our actions off of our perceived circumstances? Assumptions and fear can be dangerous. Acting on our feelings or reasoned thoughts instead of trusting God can lead us to do things that we shouldn't. Sometimes God uses opened and closed doors to lead us. Pray and pay attention to His leading.