If that's "blasphemy," then it was also blasphemy when St. Paul told the Corinthians that God was appealing (to them to repent) through him, or when he said, in another place, that now it was not he who lived, but Christ living through him.
I think "blasphemy" to you is a synonym for "paraphrasing Scripture that I don't much like or use".
No blasphemy. All who repent do so because God has given them new eyes and new ears and a new heart with which to know their salvation has been won for them by Christ on the cross.
Nor is it blasphemy to know that we now live not for and by and through ourselves, but for and by and through Jesus Christ alone.
And that fact means there is no other mediator between God and men, but Christ Jesus, and that there is no "co-redeemer." Christ on the cross, alone.
Too bad the RCC doesn't teach those two Scriptural truths.