This level of ignorance about resistance training is ubiquitous.
Lifting weights has tremendous health benefits. Improved immune system, increased basal metabolic testosterone, increased HGH in the body which is responsible for a host of health benefits on its own, increased bone density which reduces the risk of bone related injuries and disease later in life, reduced risk of diabetes, reduced risk of heart disease, and a bunch more that I can't remember off of the top of my head.
FFS, spend 30 minutes and look it up yourself.