In John 3:3, Jesus famously tells Nicodemus that to see the kingdom of God, one must be born again. Likewise, 1 Peter 1:3 and 1:23 both use this idea of a new or second birth.

1 Peter 1:3
[...] In his great mercy he has given us new birth into a living hope through the resurrection of Jesus Christ from the dead,

1 Peter 1:23
For you have been born again, not of perishable seed, but of imperishable, through the living and enduring word of God.

Where did the idea of rebirth originate from in early Christian thought? Was it borrowed from earlier Jewish themes? Was it a Greek or Roman idea? Or something new?