That is why we never give up. Though our bodies are dying, our inner strength in the Lord is growing every day.
2 Corinthians 4:16 Living Bible-TLB
For we know that when this tent we live in now is taken down—when we die and leave these bodies—we will have wonderful new bodies in heaven, homes that will be ours forevermore, made for us by God himself and not by human hands. How weary we grow of our present bodies. That is why we look forward eagerly to the day when we shall have heavenly bodies that we shall put on like new clothes. For we shall not be merely spirits without bodies. These earthly bodies make us groan and sigh, but we wouldn’t like to think of dying and having no bodies at all. We want to slip into our new bodies so that these dying bodies will, as it were, be swallowed up by everlasting life. This is what God has prepared for us, and as a guarantee he has given us his Holy Spirit.
2 Corinthians 5:1-5 TLB
There are many blessings in growing older, but if we live long enough we will experience aging. Long life on this side of eternity means we have bodies that will wear out. We can work on keeping fit but it is God's grace that makes that work. So in this, we grow old gracefully. However, the future God has promised us is not in the dying bodies our souls inhabit now, but in the inner strength of our spirits which He is renewing day by day. God has promised us new bodies in His Kingdom and He has left the Holy Spirit to indwell us to prepare us for everlasting life. Thank God now for both the old and the new—in that order!