2 Peter 3:9

The Lord is not slow in keeping his promise, as some understand slowness. Instead he is patient with you, not wanting anyone to perish, but everyone to come to repentance

From a similar question in Christianity SE

It's true that some Calvinists take a different approach and suggest that "all" in 2 Peter 3:9 refers only to Christians

So.... God speaks to the people whom He knows that they are Jesus believers :
I am patient with you.
I don't want anyone from you to perish.
I want everyone from you to come to repentance.

My question is :
How come God doesn't want Jesus believers to perish and God wants Jesus believers to come to repentance ? Aren't Jesus believers already a repented people (because elected) then impossible to perish ?

Thank you.