Psalm 139), and with Him watching over me, I don't need a guardian angel.
The word 'angel', though is so much more than that. The Greek is ἄγγελος (angelos), and this in turn has derived from translating the Hebrew (מלאך) mal'akh in the Septaguint. Both words mean 'messenger' in both sacred and secular contexts. An angel does not have to literally be a heavenly being sent from God to meet us and bring a message. Is it not angelic to speak the word of God into the world? Sometimes the right word at the right moment can change a life.
Last night, I was talking at great length to The Wife. I was feeling a little under the weather, and was beginning to doubt myself and, worse, God. Nothing he said could do more than reinforce the knowledge I was repressing within myself. I was so determined that I was going to feel bad about myself that I wouldn't let him in. Whilst we were talking, he was travelling by train. As he got up to get off the train, a woman who had been sat nearby passed him a piece of paper. On that paper, she had written a message that affirmed my worth in the eyes of God and The Wife's value as a child of God and a very dearly beloved friend. The fact that she had cared enough to write that note touched me very deeply. All my doubts seemed to melt away, and the pain just didn't matter. In that moment, she was nothing less than an angel of God, a messenger from my Father.
We may each be an angel to someone, whether we know them or not. I hope if I were ever called to be, I would have to courage to take that precious commission. I still pray for those people who have been angels in my life, and thank God for their ministry.