Now faith is being sure of what we hope for and certain of what we do not see.
The phrase, being sure, in the original language is the Greek word, hupostasis (hoop-os'-tas-is). It can be translated to mean: a setting under (support), i.e. (figuratively) concretely, essence, or abstractly, assurance:--confidence, confident, person, substance.
*Strong, James, LL.D., S.T.D., The New Strong’s Expanded Exhaustive Concordance of the Bible, Red Letter Edition (Expanded With the Best of Vine’s Dictionary of Old & New Testament Words) (Nashville: Thomas Nelson, 2010).