The “old-self,” described in Romans 6, 7 and 8, is an inherited animalistic bias of selfishness, based in survival instinct. Its origin is a feature given by God in your physical life (Eve “desired” before she sinned). ~ Jo Helen Cox in GOD MAKES US HOLY manuscript

Desire first. Is that how it works?
When I mess up, do I desire it
before I follow through?
It doesn’t feel that way.
It feels like an obsession.
Okay, it is an obsession
but I can go for months,
for long times without the pull
and then it’s there, a raving maniac,
an act that seems to happen
with no preface. But there is one.
It may be desire,
but not really for the sweets.
It’s a desire for acceptance,
for peace, for self-confidence,
for fitting in. That’s the desire.
But you can’t buy peace
like you can a fritter.