To exercise faith is to build upon a solid foundation.
And this idea is suggested in lsaiah 28:16: "Thus saith the Lord God, Behold, I lay in Zion for a foundation a stone, a tried stone, a precious corner stone, a sure foundation;...."
He that believeth, that is, builds upon the sure foundation, will stand fast when "the overflowing scourge" (Isaiah 28:15)passes through. We can build upon faith, because it is substantial; it is "the substance of things hoped for. (Hebrews 11:1)."
E.J. Waggoner