What is the importance of a beard in judaism? Please, what is the deeper meaning?

There is no obligation to grow a beard, just sideburns and not to shave one's beard with a razor, (see my recent responsa on the issue…). Hassidim and kabbalists have a special idea in growing a beard, firstly, to differentiate Jews from gentiles. Also, the individual hairs (which aren't too attractive) combine together to show the beauty of "Tiferet", where the individuals comprise an attractive whole (like trees in a forest and blades of grass). There are other kabbalistic ideas, but we'll leave them for those who do everything according to kabbala.