You *can’t *know with certainty in this life. No one living is ‘saved’. As long as you’re alive, you can sin. Only on Judgment Day, after you’ve died, will you know, when God Himself passes judgment upon you. The whole concept of being ‘saved’ in this life is based on a gross misinterpretation of Paul, he who didn’t personally know Jesus.
While I agree with you that the nature of sin has not changed, and that sin still separates us from God, even after we are born again, and that we await judgement before God, your post seems to imply that it was paul who misinterpreted the gospel.
I also disagree that Paul did not personally know Jesus. Acts 9:27-28
27 But Barnabas took him, and brought him to the apostles, and declared to them** how on the road he had seen the Lord**, who spoke to him, and how at Damascus he had preached boldly in the name of Jesus.
Jesus personally catechized Paul.
2 Cor 12:2-5
2 I know a man in Christ who fourteen years ago was caught up to the third heaven - whether in the body or out of the body I do not know, God knows. 3 And I know that this man was caught up into Paradise - whether in the body or out of the body I do not know, God knows - 4 and he heard things that cannot be told, which man may not utter. 5 On behalf of this man I will boast,
Gal 1:11-13
11 For I would have you know, brethren, that the gospel which was preached by me is not man’s gospel. 12 For I did not receive it from man, nor was I taught it, but it came through a revelation of Jesus Christ.
Paul’s acquaintance with Christ did not come until after the Resurrection, but it was quite extensive.
I will agree that some people read the Pauline epistles, and create a doctrine of salvation from them which is a misunderstanding of Paul.