I am a behaviourist and so far in all my years of training dogs, including the most problematic, I have never hit a dog. If you want respect flatten him....thats is place him on his side in a flat position. This position is the ultimate submissive and puts you in the more dominant place.
That said this is about respect not about training and the comments made earlier as far as the training itself goes should be followed.
A dog that is scared of you will never be completely trustworthy anyhow!
Hope that helps..