There are angels constantly around us, luckily we cannot see the worst of them. If we could see and perceive the bad ones we would be driven mad because our fleshly brain could not handle it. God in His mercy hides many things from us that would do us harm. But also because of our fallen, fleshly nature we cannot really perceive many of the heavenly things (like the good angels) unless God allows it.
Sometimes He lets me perceive the presence of an angel, or many angels. This has happened on more than one occasion.
Recently I went into St. Bertrand to go to Holy Mass and I always come in the handicap entrance. As I dipped my hand in the Holy Water Font God allowed me to perceive (not see) the angel that was guarding that Holy Water font.
I stopped in my tracks. I was aware of him, and I could perceive that he was aware of me and as my hand hovered over the holy water font, he was looking at me.
If God allows you to perceive something, He also allows you to have some knowledge about it. I knew this angel's job was to guard this Holy Water font for all time. I knew it held a spear of light which it held at its side ready for battle if needed.
Now understand, I am a Mathematician. I analyze everything. So my first thought is, "Why did God allow this?" God wastes nothing, and if He allows you to perceive something it is either for your good or for the good of another.
Immediately my mind was racing, "Ok, what do I know and how do I use this." I know that the Angels (all of them) always face the throne of God, no matter where there assignment is. So whether an angel is assigned to protect you, a church, or a Holy Water font, they always have one face toward the throne of God.
So before I dipped my hand into the font I prayed a prayer under my breath so I knew the angel would hear it.
"Angel of the Holy Water Font, pray for me."
Then God in his grace allowed me to perceive the angels answer.
The angel nodded in assent to my request.
Angels are constantly around us, but when God allows you to perceive one (or many), you have just won the proverbial heavenly jackpot.