The most likely result of eating moldy fruit is absolutely nothing unless the person eating the mold is allergic. However, while the majority of molds are not dangerous, moldy fruit is more likely to be spoiled, and spoiled fruit may cause illness. Because mold may form on fruit without the fruit spoiling, simply cutting the moldy area off is also a solution.
Most molds are not harmful, and some are even beneficial. In fact, mold is actually a form of fungus, similar to mushrooms. Mold grows in damp environments and fruit skin, especially over a bruise on the fruit, is the perfect growing ground for it. The mold spores grow in the moisture and extend small tendrils or threads into the fruit. If the fruit is beginning to rot or tastes strange, then the fruit itself might cause the person who eats it to feel sick. Otherwise, eating moldy fruit is generally harmless.
Most people prefer to cut the section with mold off of the fruit before eating it, but this is a matter of personal preference. This is the best option, as mold can cause allergic reactions and respiratory problems in persons who are allergic to the mold. The best option is to remove the section, or cut out the mold spots before eating.