To generalize somewhat -

You want to get your chips in when you MOST LIKELY have the best hand. With JJ that would be pre-flop. On the flop with two overcards and 3 other people (who called your raise) - you PROBABLY do not have the best hand. With a push here you MAY scare a single opponent who aclled you with something like 88, but you probably not going to get A or K to fold. Against three opponents - you're getting a call here something like 80% of the time. You may try a continuation bet here, but I'll probably just check and fold.