Does God uses angels to serve and protect man:

The primary purpose of the angels is to carryout the will of God. Often, such responsibilities include serving and protecting man:

If you make the Most High you dwelling-
even the LORD, who is my refuge-
then no harm will befall you,
no disaster will come near your tent.
For  he will command his angels concerning you
to guard you in all your ways;

Psalms 91:9-11