Rom 9:1 I say the truth in Christ, I lie not, my conscience also bearing me witness in the Holy Ghost, 2 That I have great heaviness and continual sorrow in my heart. 3 For I could wish that myself were accursed from Christ for my brethren, my kinsmen according to the flesh:
Paul's passion for his Jewish brethren was evidenced by his constant misery that they were blinded from the light of the glorious gospel and that they would perish. His sorrow for them was so intense that he wished he could somehow be accursed from God in their stead.
This is what drove him to enter first into the synagogue of whatever town he entered to give the Jews first crack at the gospel message of Christ's atonement and resurrection.
Eternity was real to Paul. See, he had personally stepped outside of time and possibly even his body and experienced the glories of the third heaven of God. (II Cor 12:1-5) He had an inkling of what it meant to walk the streets of gold and be in the presence of God almighty.
That is what Paul desired for his people when their mortal lives ended and eternity began. But he knew what awaited them if they rejected or never heard the message of the gospel.
I don't suppose anyone in all of history, outside of Jesus Himself, went to greater lengths to spread the Word than this heavy hearted evangelist, church planter and martyr.
What about you? Do you care that your brethren are under the curse of sin and will be eternally separated from the Lord of glory unless they are washed in Christ's blood. No one is asking you to die for Christ at this time, just that you live for Him. You don't have to suffer ship wreck, be beaten with whips, stoned with rocks or imprisoned for preaching, just be a witness, give a tract, and say a word for Jesus as His Spirit prompts you. Be sensitive to the plight of lost sinners. Most of all, act like you really do care that people are perishing without Christ.