This thread is quite old, but I'd like to use Abraham and Abram as an example of the limitations of man's faith, and the faith of God which does appear to be inspired by a word promised. Faith comes by hearing a word from God, but until that word gets down into our spirit man / heart, it seems to remain a hope.
God promises Abram that Sarah will bear him a son, and Abram believed God, and it was accredited to him for righteousness. And yet Abram listened to his wife and agreed to go into Hagar in order to bring about God's promise. This is intriguing because Abram seems to be ignoring the word of God in order to bring about the promise of God contrary to the word spoken to him. This means that Abram's faith, although commendable, was imperfect. Of itself it couldn't lead to Sarah conceiving.
And so God returns again and changes Abram's name to Abraham (father of many nations). This forces Abraham to hear the word spoken over him all the time. He considers the impossible situation in the natural, but he keeps hearing the word "father of many nations".
Eventually the conception of God's faith (calling those things which are not, as though they are) takes place in his heart. He now can do nothing but believe and expect, and have rest in his heart about it. God's faith.
The lesson for us is that we have to keep hearing the word, and confessing it until it id conceived in our hearts. Then we're gonna rest.