My personal opinion:

don't lift weights with your goal being to get "bigger" or more "ripped." Lift weights to get STRONGER.

I'm living proof that stength training with weights is beneficial. I basically doubled the power in my left arm by working out on a simple weights and pulley system I hung from my basement rafters.

But, weights and strength training is only supplemental. It should be buffered...the majority of your training... by BOXING...on a bag, working mitts, shadow boxing, etc.