The regeneration of those that Christ died for, is due to Christs resurrection from the dead, Peter writes 1 Pet 1:3
3 Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy
hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead,
The prep "by" here is dia and means:
: through, throughout, by the instrumentality of, (b) acc: through,
on account of, by reason of, for the sake of, because of.
The words begotten us again is the word anagennaó:
/aná, "up, again," which intensifies
1080 /gennáō, "give birth") – properly, born-
again or "born from
on high."
313 /anagennáō ("born again, from above") is used twice in the NT (1 Pet 1:3,23) – both times referring to God
regenerating a believer (giving a supernatural,
new birth).
to produce again, beget again, beget anew; metaphorically: τινα, thoroughly
to change the mind of one, so that he lives a new life and one conformed to the will of God, 1 Peter 1:3;
Strong's Greek: 313. ἀναγεννάω (anagennaó) -- To beget again, to regenerate, to be born again
Thats were our believing comes from, thats part of the newness of life
Christs death put away our sins, hence justice satisfied, new life is given ! 25