21 “For to me, to live is Christ, and to die is gain. 22 But if I am to live on in the flesh, this will mean fruitful labor for me; and I do not know which to choose. 23 But I am hard-pressed from both directions, having the desire to depart and be with Christ, for that is very much better; 24 yet to remain on in the flesh is more necessary for your sakes. 25 Convinced of this, I know that I will remain and continue with you all for your progress and joy in the faith,26 so that your pride in Christ Jesus may be abundant because of me by my coming to you again.”
Paul has a singular mindset and focus: Christ. His view was black and white. If he were to remain alive, this would yield fruit for the Gospel and love for his fellow Christians. But he also knows he has everything to gain by dying because Christ awaits him in Heaven. So, because of Paul’s singular focus, he has no fear of death while having supreme purpose in life.
Convinced of this, I know that I will remain: Paul believed that his imprisonment would not result in his death and that he would be able to continue in the labor of the Gospel. Perhaps this shows some of the personal relationship that Paul had with Christ. The Holy Spirit was evidently reassuring him in the midst of these circumstances.