The following passages are all from Romans 4:
That famous promise God gave Abraham—that he and his children would possess the earth—was not given because of something Abraham did or would do. It was based on God's decision to put everything together for him, which Abraham then entered when he believed.
Abraham was first named "father" and then became a father because he dared to trust God to do what only God could do: raise the dead to life, with a word make something out of nothing.
When everything was hopeless, Abraham believed anyway, deciding to live not on the basis of what he saw he couldn't do but on what God said he would do. And so he was made father of a multitude of peoples.
Abraham didn't focus on his own impotence and say, "It's hopeless. This hundred-year-old body could never father a child." Nor did he survey Sarah's decades of infertility and give up. He didn't tiptoe around God's promise asking cautiously skeptical questions. He plunged into the promise and came up strong, ready for God, sure that God would make good on what he had said. That's why it is said, "Abraham was declared fit before God by trusting God to set him right."
