And last of all He was seen of me also, as of one born out of due time. – 1 Corinthians 15:8

Though Paul was, in a spiritual sense, “born out of due time,” he was truly born again; and those persons, who have been converted at singular times, and under strange circumstances, have been really converted. How do we know that Paul was born again, and that he was called to be an apostle of Jesus Christ?

I answer, because he had seen the Lord. After mentioning those who saw the risen Christ, he says, “Last of all He was seen of me also, as of one born out of due time.” The first, evidence that he was an apostle was that he had actually beheld the Lord. Now, in a spiritual sense, one of the marks of a true believer is that he has seen the Lord. My dear friend, if you have looked to Christ for forgiveness…if you have by faith seen Jesus on the cross, and truly trusted Him, you are as much saved as the man is who believed in Christ fifty years ago. Looking to Jesus is the evidence that we are born again; and happy is everyone who can truthfully say, concerning Christ.” He was seen of me also.” “I looked to Him; He looked on me; and we were one for ever. I trusted to Him, and therefore I am saved.” If you can say that from your heart and the Holy Spirit bears witness that what you say is true, you. need, not raise any question about your new birth. If thou art trusting in Jesus, it is well with thy soul in time and to eternity. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2663.cfm