The ability to think probabilistically is important for many reasons. Lack of it makes one prone to a variety of irrational fears and vulnerable to scams designed to exploit probabilistic naivet, precludes intelligent assessment of risks, ensures the operation of several common biases, impairs decision making under uncertainty, facilitates the misinterpretation of statistical information, precludes critical evaluation of likelihood claims, and generally undercuts rational thinking in numerous ways.
Probabilistic thinking is essentially trying to estimate, using some tools of math and logic, the likelihood of any specific outcome coming to pass. It is one of the best tools we have to improve the accuracy of our decisions. In a world where each moment is determined by an infinitely complex set of factors, probabilistic thinking helps us identify the most likely outcomes. When we know these our decisions can be more precise and effective.