I could probably say at the point of Grace. I have in mind the confession of St. Paul in Gal 2:20-21
20 I have been crucified with Christ; it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me and gave Himself for me. 21 I do not set aside the grace of God; for if righteousness comes through the law, then Christ died in vain.”
When did Paul's crucifixion with Christ happen? At the Cross? On the road to Damascus? Or at Damascus when Ananias baptized him (or in our language when God baptized him)?
I cast my vote for the last one because of what he wrote in Romans 6:1-6. I am fairly convinced of this, that it happened at Damascus with Ananias. What about you?
I would have agreed or asserted this probably 3-4 years ago, but one thing I learned with Concordians is that they simply say what Scripture says without excuse or rational summersaults.