Q. 1. What proof is there that Guardian Angels exist?
A. 1. I can think of two verses in the Holy Bible that makes reference to angels watching over us, one being in the Old Testament and the other one being in the New Testament.
Those verses are:
"For he will command his angels concerning you to guard you in all your ways." [Ps. 91:11]
"Take care that you do not despise one of these little ones; for, I tell you, in heaven their angels continually see the face of my Father in Heaven." [Mt. 18:10]
For those who do not believe in the Holy Bible, no proof can be provided to them.