In general, one can express this two-way implication by if and only if (shortened in mathematics to iff). But in this case it presents two problems:
- It requires a restructuring that is less elegant than the original.
- It changes "may not" into an absolute "cannot".
One's potentials can be deeply explored, if and only if one discovers shortcomings that create the opportunities to do so.
I don't think you'll find a phrase that can accurately express "if A then B; if not A then perhaps not B". I think your original sentences are fine, and could just benefit from removal of the obvious redundancy:
Shortcomings are actually valuable opportunities to explore deep into one's potentials. Without shortcomings, one may not be able to find those opportunities.