We were given five perceptions or "senses" (taste, touch, sight, hearing, and smell). Faith is also a "sense". It gives us evidence of the invisible, spiritual world, but unlike our five senses, faith cannot be measured in a laboratory, it must be understood spiritually.
When we see things to our physical eyes we confirm and affirm that it is so! But faith helps us to see the invisible, that which we cannot see or touch. I'll put it to you this way, faith is a belief beyond reason. It's beyond intellect, beyond understanding. It is a willingness to rely on, trust in, that which we cannot see or comprehend.
By faith kingdoms were subdued, Justice was administered, promised blessings were obtained, it closed the mouths of lions, extinguished the power of raging fire, help escape the edge of the sword, out of weakness we were made strong, became mighty and unbeatable in battle, it put enemy forces to flight, and women received back their dead by resurrection to name a few. (Hebrews 11:33 - 35)
Now on the other hand, because of their faith people were tortured, imprisoned with chains, stoned, sawed in two, lured with tempting offers to renounce their faith, oppressed, cruelly treated. "And all of these, though they gained divine approval through their faith, did not receive the fulfillment of what was promised, because God had us in mind and had something better for us, so that they, these men and women of authentic faith would not be made perfect (completed in him) apart from us!(Hebrews 11: 39)
"They looked forward to Jesus and his work, we look at it from behind and enjoy the fruits of his work." -David Guzik
And that my friends is the grace of faith.