Exactamundo.
Therefore, the promise comes by faith, so that it may be by grace and may be guaranteed to all Abrahams offspringnot only to those who are of the law but also to those who have the faith of Abraham. He is the father of us all.(Romans 4:16)
I appeal to you for my child Onesimus, whose father I became while I was in chains. (Philemon 1:10)
"In Christ Jesus I became your father through the gospel." -Paul - (1 Cor. 4:15)
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That's the difference you're missing.