2 Corinthians 4:16-18 (NKJV)
Therefore we do not lose heart. Even though our outward man is perishing, yet the inward man is being renewed day by day. For our light affliction, which is but for a moment, is working for us a far more exceeding and eternal weight of glory, while we do not look at the things which are seen, but at the things which are not seen. For the things which are seen are temporary, but the things which are not seen are eternal.
I can personally testify to it: our bodies are wearing out. I can also say however that I am closer to my Lord than when I first became a Christian; my soul is being renewed. Carry that to it's logical conclusion: death itself is nothing to lose heart over for it is at that point that our souls will most rejoice to see our savior face to face. All of our sufferings will seem but a mere inconvenience compared to an eternity of glory.
This earth we live on is mostly empty space. Consider the atom, the building block of all matter. If the nucleus of an atom were the size of a pin head, the nearest electron would be about 100 yards away. A neutrino is a particle like an electron but without a charge; it does not react magnetically with any other particle. Scientists say that a neutrino can fly straight through the earth without hitting anything. It makes sense when you realize that the actual matter of the earth, protons, neutrons, and electrons, are just a nearly empty lattice work of particles connected magnetically. With the peculiar implications of quantum physics, we might find out that our whole existence is but an elaborate digital hologram, a bit like The Matrix. We do learn in the Bible of a battle taking place in the spirit world around us, and of angels making appearances in our world.
On the other hand eternity is permanent. It existed before the world and it will continue to exist afterwards. The Bible says this world is passing away. The stuff we can see and touch is less real than that which we can only contemplate and dream of.
The most incredible event in all of human history is when God himself stepped out of Eternity into time and space taking upon himself human flesh. He became our kinsman, here to redeem us.