do u think justin bieber is strong?

ya he is this strong

Hmm.. Good question.(For once)
It depends what あなた mean によって strong. あなた probably mean strength and stuff. He's 16 and appearantly he started working out and stuff. He's probably not the strongest guy to break a brick with his bare hands but he's probably got his line of strength.
When it comes to willpower, I surely can't say for sure. He's probably not so easy to crack when it comes to like an mental invasion when someone would try to mindscrew him but あなた never know.

well for me i actually I do think that he is really strong

yeah probably i hope so

i think he is strong

yes

of course did u see his pak

yea

yes

yeah, I think he did some work-outs with taylor Lautners trainer, so i guess..