The are two very small but very important words in the Christian vocabulary: as if. We are called to live by faith, not by sight, but to live truly by faith we have to live as if it were by sight. Moses gives us an example: "he persevered as if seeing the One who is invisible" (Hebrews 11:27). To persevere as if seeing is to live by faith.
In this, God asks quite a lot from us, but evidently it's the only way to prove our love and to be found worthy of his heavenly kingdom. St Peter exhorts us: "Love Him without having seen Him; believe in Him though you do not now see Him" (1Peter 1:8). For those of you who are more advanced, the Greek can also be translated as a declaration of fact: "Without having seen Him, you love Him; though you do not now see Him, you believe in Him."
This was the essence of Pascal's famous wager: Live for one year as if you fully believed all that the Scriptures and the Church teach, and put it into practice diligently the whole time, and I'll bet that at year's end you will in fact really believe and will freely and lovingly put it into practice thereafter.
Much of our spiritual life, whether we like it or not, has to be lived on that "as if" basis. We don't see, we don't fully understand, we have numerous unanswered questions, we have struggles with things that we'd really wish could be some other way. But we believe and trust in God, so we live as if we had the answers (which means we live as the Gospel directs, without excuses, procrastination, or rationalization). This is not easy, but it is what a life of faith requires.
Look again at Moses, at the context in which it was said that he persevered as if seeing: "he chose to share ill-treatment with the people of God rather than to enjoy the fleeting pleasures of sin. He considered abuse suffered for the Anointed One greater wealth than the treasures of Egypt, for he looked to the reward... he was not afraid of the anger of the king..." (Hebrews 11:25-27).
Persevering as if seeing is hard work, but its benefits will be eternal. We will have to sacrifice certain ideas, opinions, activities, pleasures, and worldly behavior for the sake of living by faith in the Invisible One, who promises eternal life to those who believe in Him and do his will. After all, faith is about believing and embracing "things not seen" (Heb. 11:1). So don't let it be an obstacle for you that the Mysteries of God are so profound as to be invisible or intangible or not subject to scientific verification. Persevere anyway, as if...