A gap year allows participants to find passion in their life.
It’s best to avoid this phrase altogether. First of all it’s redundant, and secondly it’s easy to introduce error. I know my own students always write ‘their’ (plural) ‘life’ (singular).
The following are possible:
Once again, the first of these examples is preferable – we know that you’re talking about the participants’ lives and not the lives of cats and dogs!