Romans 4:18,20,21 "In hope against hope he believed ... with respect to the promise of God, he did not waver in unbelief but grew strong in faith, giving glory to God, and being fully assured that what God had promised"

We know that Abraham believed God, and it was credited to him as righteousness.  What does that saving faith look like?  In Calvinistic terms it's called perseverance, saving faith is a faith that endures. (Matthew 10:22)

Abraham believed the promise of God (that he would be a father of many nations) despite the fact that he was old in age and Sarah his wife could not even bear children.  Abraham did not grow weary and demonstrated or vindicated his faith by willingly sacrificing his promised son Isaac.  God intervened and spared Isaac's life but it was a demonstration of Abraham's perseverance of faith that was credited to him as righteousness.

Does our faith have the traits of a persevering faith?  One that would pass the test and endure?  If not, it is a dead faith that will not save.