There are several fascinating explanations regarding the meaning of Lag b'Omer and why 'holy fires' play such a prominent role.

Whatever your belief in angels might be, the most important thing is to remember that there is a Creator of all of us who wants a direct and personal relationship with us ,without any intermediaries! 

In giving us the Torah in the desert, God was freeing us not just from the reality of slavery, but also from the mentality of slavery.