not a command from Allah, but it's sunnah i mean prophet mohammed (peace be upon him) used to let his beard grow, so all his companions and those who follow him let their beard grow. hey not all muslim men do so because i think it's not a must.

I have a bear alhmd llah and I have it because I love to be like prophet Mohammed PBUH in everything but it`s not command in the Quran

Surely it's not a "Command" ... Let me explain it in other way ...if you're a big fan of a "Rock star" let's say don't you imitate him the way he dressed like,his haircut his moves maybe even quote him in your daily speech???....and also there are other fans who truly like this star but don't exactly involve him in those personal details ...right? that's exactly what is happening with the guys with the "beard" .Our prophet used to have it,so they wanted to have it as well.Actually they're is another bunch of people that put "misk" the perfum that was known at the time ,also the clothes...and so on ....On the other hand they're others who truly love and beleive at the prophet but don't have that "beard" they consider it optional it's just a look no more ...You see? this called "sunnah" wich can be translated to "the life style of the prophet...." don't hesitate to ask more as long as we are here :D