'Circumstances' in the Bible

Under what circumstances was it credited? Was he circumcised or uncircumcised? He had not yet been circumcised, but was uncircumcised.

Hoping in spite of hopeless circumstances, he believed that he would become "the father of many nations," just as he had been told: "This is how many descendants you will have."

And not only that, but this too: Rebekah conceived twin sons by one man [under the same circumstances], by our father Isaac;