Not trying to convert you back to Buddhism, but if that's you only objection, I have to tell you Karma does not require rebirth. In fact the Buddha refused to

Not trying to convert you back to Buddhism, but if that's you only objection, I have to tell you Karma does not require rebirth. In fact the Buddha refused to respond one way or another when asked what happens to us after death.¹ Karma can be seen as operating from moment to moment. It's easier to think of it as 'past conditions', i.e. the initial conditions that led to our current state. This applies physically as well as psychologically. If you like the image of non-linearity, see². 1: https://en.wikipedia.org/wiki/The_unanswered_questions https://en.wikipedia.org/wiki/The_unanswered_questions 2: https://www.dhammatalks.org/books/KarmaOfQuestions/Section0009.html https://www.dhammatalks.org/books/KarmaOfQuestions/Section00...