At Caesarea there was a man named Cornelius, a centurion in what was known as the Italian Regiment. 2 He and all his family were devout and God-fearing; he gave generously to those in need and prayed to God regularly. 3 One day at about three in the afternoon he had a vision. He distinctly saw an angel of God, who came to him and said, “Cornelius!”4 Cornelius stared at him in fear. “What is it, Lord?” he asked.The angel answered, “Your prayers and gifts to the poor have come up as a memorial offering before God. 5 Now send men to Joppa to bring back a man named Simon who is called Peter. 6 He is staying with Simon the tanner, whose house is by the sea.”7 When the angel who spoke to him had gone, Cornelius called two of his servants and a devout soldier who was one of his attendants. 8 He told them everything that had happened and sent them to Joppa. Acts 10:1-8
Like the Ethiopian Eunuch, like the worshippers in Jerusalem at Pentecost, like the disciples in Acts 19 who had only heard of the baptism of John, Cornelius was an Old Testament saint. He believed in Yahweh, followed the law, confessed his sins but yet wasn't a New Testament saint. He did not know of the death and resurrection and the substitutionary atonement of Jesus. Where would he have gone if he died not knowing of Jesus? Well, we will never find out because God was making sure that didn't happen in supernatural ways. He sent Phillip to run alongside a chariot then whisked him away to another place. He sent Simon to Joppa and sent an angel in a vision to tell Cornelius where he needed to go to find him.
We are no longer in those transition times. People can go to church, give to the poor, raise good families, be good citizens but that doesn't amount to anything - they still need Jesus and we need to tell them. As good as Cornelius was, he still needed Jesus. We tend to go to the dregs of society because they aren't good people - we know they need Jesus in the bars and in the prisons. However, do we tend to shy away from the "good" people thinking they already have it all together so they aren't in need of Romans 3:23? Cornelius stands as a testimony that no matter how "good" we might be or are trying to be, good deeds don't get us to Heaven, only faith in Jesus does.
If someone comes to your mind, maybe you are in "Joppa" for the express purpose of reaching that person for Christ. Your acquaintance with them is maybe the only doorway to eternal life that they will ever get. Tell them about Jesus and let the Holy Spirit do the work. You don't have to and can't save them but God can. Your best ability is availability. Like Cornelius, follow the Lord's leading.