You have touched on a very important point. Every believer's faith will be tested, and some will be tested very severely, while others not as much. For God our faith has to be tried, tested, and proven to be genuine "gold". Therefore it must go through the furnace of testing and affliction, and come out refined and purified on the other side. At the same time the Bible tells us that God will not test us above that which we are able to bear.
Consider Abraham, who waited for a son for 100 years, and after God gave him that son of promise, He asked that Abraham sacrifice him like a lamb. Imagine having to face that test personally, and take your own son's life at God's command! And James tells us that since Abraham passed this test with flying colors, his faith was shown to be genuine. Therefore Abraham is "the father of us all".
Consider Abraham, who waited for a son for 100 years, and after God gave him that son of promise, He asked that Abraham sacrifice him like a lamb. Imagine having to face that test personally, and take your own son's life at God's command! And James tells us that since Abraham passed this test with flying colors, his faith was shown to be genuine. Therefore Abraham is "the father of us all".
In Gen 22, when Abraham and Isaac left the men traveling with them, Abraham told them I and the lad will go yonder and worship, and come again to you (Gen 22:5). Abraham included Isaac in the statement "and come again to you". He did not say "I and the lad will go yonder and worship, and I will come again to you".
Abraham believed God's promise that his progeny would be innumerable as the stars in the heaven and as the sand upon the seashore (Gen 15:5, Gen 22:17); therefore, Abraham believed he and Isaac would both return from the mountain.
That is the faith of Abraham. We have the same faith Abraham had. However, faith is either weak or strong depending upon how that tiny grain of faith God has placed within us is utilized. Jesus compared faith with a mustard seed … a teeny, tiny seed which when grown it is the greatest among herbs and becomes a tree (Matt 13:32).