Good Idea Melman! Retire the belt ... Violence won't get any point across, probably make the dog MORE defiant and afraid on top of that. YIKES!
Getting some training help for your pup would be good for you, your wife AND your kids to attend. So EVERYBODY in the house is on the same page and using the same commands. This will help your pup and your family greatly.
To me the love and affection my boys give me is greater than the annoying habits they have (like lack of housebreaking) haha I work with them every single day still (they are going to be 2 in a couple days)
Im glad you sought advice for your dilemma with your pup. I really do hope that you follow up and listen to some of the advice and take it to heart. Your family should be enjoying your pup and CAN ... but at this point, what was not taught to him as a puppy needs to be taught to him as an adult, and he is more set in his ways so this is going to take more time & patience. But these guys are no dummies, he'll get it, he really will!!! Good Luck!!!!