If I have celiac disease and eat gluten anyways, what will happen to me?

Undesirable things! A person with celiac disease gets strong allergic reactions to gluten in the small intestine, which causes the lining of the intestine to lose its ability to absorb nutrients, vitamins, minerals, etc... If he continues to eat gluten, he can become anemic, lactose intolerant, and have diarrhea or irritable bowel, tummy pains, vitamin deficiency, etc...
Poorer Health. In the short term you will feel the affects of an allergic reaction. But in the long term the effects of under-nutrition will have significant effects on the overall function of the rest of your body. The body needs nutrients to function optimally. When these nutrients are not absorbed well like with gluten exposed Celiac disease the whole body can suffer.
Celiac Disease. Whatever usually happens when you eat gluten is what might happen this time. Usually it is limited to GI issues.