It is tough to accept that dying is something we have to do. I would go so far as to call it part of my God-given mission. God has kept me on this planet for a long list of things that He wants to do through me. Eventually it will be enough, and the remainder of God’s mission will be carried on by other people. All I have to do at that point is to let this sin damaged body go to the grave.
If I have my sins forgiven by God, then my destiny at death is eternal life with Him starting in Heaven. That is a great thing for me. I can have that only by being connected to Jesus.
The connection to Jesus is something only God can do. Jesus made it the way to eternal life by fulfilling God’s Law and paying the spiritual punishment of my sin by being forsaken by God on the cross. The connection to this is done by God too. Only He can get through to a person and make the connection usually through baptism. Once connected (saved) priority one is remaining connected. Keep feeding the faith by Word and Sacrament, surround yourself with other supportive believers, be a person who knows God through prayer, always have your radar on opportunities to do the work of the Kingdom of God. That is what you can do. God will keep you from falling.
When you finally physically grind down to the point where you can die, it will be an emotional balance between wanting to do more, but knowing you’re done, and being eager for what comes next. Dying well, means looking forward:
16 So we do not lose heart. Though our outer self is wasting away, our inner self is being renewed day by day. 17 For this light momentary affliction is preparing for us an eternal weight of glory beyond all comparison, 18 as we look not to the things that are seen but to the things that are unseen. For the things that are seen are transient, but the things that are unseen are eternal.
2 Corinthians 4:16-18 (ESV)
How should we manage “grinding down”/”wasting away”? There is the stewardship of our bodies to consider. On the one hand, I want to get out of here. This life on Earth doesn’t compare favorably to Heaven. On the other, the work of the Kingdom of God is a good thing in a place that really needs it and I want to be of service. With this tension in mind, I believe we do our best to a point.
To be considered good stewards of the body, we definitely don’t cut corners to hasten our death: no suicide, no medical non-compliance, no clearly bad habits, no unnecessarily risky behavior. There could be situations where we risk martyrdom, but we don’t go looking for it.
We are not asked to extraordinary things that prolong our lives into an artificially extended period where we will be of little use. I knew one man whose lungs were severely damaged by COVID. It was determined that he could never get off of a vent, so he stopped it, and died. I support that decision. That isn’t suicide.
Sometimes the decision isn’t so black and white. Family discussions and family prayer are necessary then. People tend to error on the side of doing too much, because they are not ready to grieve. You are not doing the person a favor, if they are in Christ.
Now I am going to really meddle. What about diet and exercise? If you have a clear medical diagnosis, like diabetes, where you need to be strict about diet. I would consider that to be not just a personal but also a spiritual obligation. We can all follow theories about how best to eat or care for our bodies, but the fact is that many extreme regimens often prove to be wrong in the end. I think the best stewardship of the body at any point in our lives is moderation in everything. If you follow conscience on this, you are doing well.
You may say that God determines the day of our death, and there is nothing we can do to change it; but the Bible says God knows the day of our death. Its date is not pre-determined, it is contingent. God just knows everything. With this in play it is possible to miss out on some of what God plans for us.
0 For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them.
Ephesians 2:10 (ESV)
Living, aging, and dying well is to complete that which God has prepared beforehand for us. He doesn’t give us a printout so that we can be prepared or look ahead. We can only be formed for service and ready to do it until the end.