That Paul would continue to live was not the question. The question was whether that would be in the body or outside of the body, which of course is an euphemism for death, but the fact that it is not being called death is showing you the spiritual reality that Christ brought to light for believers.
Paul is getting personal here. While in some other parts of the scriptures, Paul is laying out spiritual truths that are valid for every Christian, here, he is laying bare his heart as he faces the prospect of death in the hands of a fellow human because of his Christ advocacy, which was threatening for some people.
The reason the threat of death was not enough to shut him up or to make him deny Christ was because of the promise of the afterlife.
But listen to what Jesus said:
But whoever denies me before people, I will deny him also before my Father in heaven. (Matthew 10:33: )
And we know we serve a Lord who has overcome death. Hallelujah!
For Paul, his continued life on earth was for him to continue to flow in the ministry. He called it productive work--his gift, his ministry, his office would continue to affect lives; he would continue to sow more seeds of the word as a minister of the word.
But let's not overlook the word "work." The concept of laboring in the world is sometimes regarded by the naysayers as something for lazy people, as an excuse, as a dead-end life. But that is not what Jesus sees it.
The one called to give God's household their food had to do it; otherwise, he would be punished when the master comes back.
Who then is the faithful and wise slave, whom the master has put in charge of his household, to give the other slaves their food at the proper time? Blessed is that slave whom the master finds at work when he comes. I tell you the truth, the master will put him in charge of all his possessions. But if that evil slave should say to himself, ‘My master is staying away a long time,’ and he begins to beat his fellow slaves and to eat and drink with drunkards, then the master of that slave will come on a day when he does not expect him and at an hour he does not foresee, and will cut him in two, and assign him a place with the hypocrites, where there will be weeping and gnashing of teeth. (Matthew 24:45-51)
But Paul has no such worry. He had thrown himself into the ministry of the word since his road to Damascus experience (Acts 9). He did not shut his mouth in the face of the death threats.
Are they servants of Christ? (I am talking like I am out of my mind!) I am even more so: with much greater labors, with far more imprisonments, with more severe beatings, facing death many times. Five times I received from the Jews forty lashes less one. Three times I was beaten with a rod. Once I received a stoning. Three times I suffered shipwreck. A night and a day I spent adrift in the open sea. I have been on journeys many times, in dangers from rivers, in dangers from robbers, in dangers from my own countrymen, in dangers from Gentiles, in dangers in the city, in dangers in the wilderness, in dangers at sea, in dangers from false brothers, in hard work and toil, through many sleepless nights, in hunger and thirst, many times without food, in cold and without enough clothing. (2 Corinthians 11:24-27)
He measures his servanthood by his sufferings, meaning the kinds of things that were thrown at him that he had to continue to move on to work to build up the body of Christ.
He plowed ahead even as he faced severe conflicts at every turn. But lest we give Paul too much credit, he said this:
1 Corinthians 15:10: But by the grace of God I am what I am, and his grace to me has not been in vain. In fact, I worked harder than all of them—yet not I, but the grace of God with me.
I don’t know which I prefer
He is saying, on a personal note, he was torn between being with Christ and continuing his productive work. He didn't think he had to stay because he believed no one could replace him. He did not think he was irreplaceable. Only Christ is irreplaceable. He did not have the Elijah complex.
Elijah told God that he is the only devotee to him. But God said he has 7000 who have not bowed to Baal, and asked him to anoint Elijah to replace himself (1 Kings 19:9-18).
Truly, we can only do our best and leave the rest. But somehow, in the specialness of the gift, we are blinded to the fact of our replaceability.
Continuing where we left off about the theology of the body, Paul is saying that being in the body allows him to continue having productive work.
That further highlights the value of the body. God created the body, and when he said that what he created was good, in the book of Genesis, part of what was good is the body.
The theology of the body also touches on the theology of work. God made the body for productive work. And even the functioning of spiritual gifts in spiritual service is serious work. The result of that is fruit that accrues to eternal life.
Not everyone is called to do what Paul did, the kind of work, the preaching of the gospel, and the challenges that come with that. But what is valid for everyone is that the body is made for work, beginning with Adam.
Even Jesus said that he had to work the work of him that sent him (John 9:4). He was a carpenter, right? Rest is meant to be an interlude between work. The bible frowns at people living for pleasure.
But the one who lives for pleasure is dead even while she lives. (1 Timothy 5:6)
treacherous, reckless, conceited, loving pleasure rather than loving God. (2 Timothy 3:4)
As for the seed that fell among thorns, these are the ones who hear, but as they go on their way they are choked by the worries and riches and pleasures of life, (Luke 8:14)