This is my own verse by verse, brief commentary on this passage, in an effort to make it a little clearer. Read the passage, and then my commentary follows it. Please let me know if it helps you. I hope it encourages you.
2 Corinthians 4:16-5:8
4:16 Therefore we do not lose heart. Even though our outward man is perishing, yet the inward man is being renewed day by day. 17 For our light affliction, which is but for a moment, is working for us a far more exceeding and eternal weight of glory, 18 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.
5:1 For we know that if our earthly house, this tent, is destroyed, we have a building from God, a house not made with hands, eternal in the heavens. 2 For in this we groan, earnestly desiring to be clothed with our habitation which is from heaven, 3 if indeed, having been clothed, we shall not be found naked. 4 For we who are in this tent groan, being burdened, not because we want to be unclothed, but further clothed, that mortality may be swallowed up by life. 5 Now He who has prepared us for this very thing is God, who also has given us the Spirit as a guarantee.
6 So we are always confident, knowing that while we are at home in the body we are absent from the Lord. 7 For we walk by faith, not by sight. 8 We are confident, yes, well pleased rather to be absent from the body and to be present with the Lord.
4:16. We should not lose heart over troubles and sickness and pain in the body. Though our body is perishing, our inward man is being renewed day by day; that is, our inner self is growing daily to be more like Christ.
4:17. The more we are afflicted in this life with suffering (especially if we suffer while doing what is right), the more we will have the opportunity to grow in Christ likeness. In fact, the afflictions we endure will work for us just like lifting weights; they will help to build up our spiritual muscles. And the future glory we will receive will far outweigh the affliction.
4:18. So we should not be concerned about the sufferings of our body now, for our bodies are only temporary. We should be more aware of, and look forward to, our new bodies and all the glorious things to come. Though we can’t see these things, they are real and eternal and glorious.
5:1. The bodies we have now are nothing compared to what our new bodies will be like. Our bodies now are like flimsy tents and will soon be destroyed. Our heavenly bodies, however, will be like a sturdy building, which will last forever—because they will be built by God Himself.
5:2. Just thinking about these old, warn out bodies of ours, and the fact that we will soon be in our new bodies, makes us long in anticipation of when we will receive them. It will be just like putting on a new set of clothes!
5:3. Don’t ever think that after we die, in our new life we will float around heaven as spirits. No no! We will receive actual, material bodies made to last for eternity. I think they will look much like our bodies now, except, as I said, they will last forever—and also they will be super bodies (what all we will be able to do I don’t know).
5:4. We are burdened now not because we want to be rid of this earthly body. Deep down we really like our body; we just want a body that will last, and not be diseased and worn down. So, I think we really want our same bodies; we just want them to be upgraded, made better.
5:5. Are we afraid of dying and getting new bodies? Well, we don’t have to be if we trust in God. He has prepared us for that day, and He has given us the Holy Spirit to comfort us and assure us that the entire procedure will go smoothly as He has planned.
5:6. Therefore, we live in confidence and with the understanding that as long as we are in this earthly body we are not really at home with the Lord.
5:7. In view of this present reality, we must keep looking to Him and trust Him rather than look at our own troubles.
5:8. Yes, we so long for out new bodies and our new home—where we will always be with the Lord.