Allah sends his angels on earth to help people. If a person calls upon Allah for help then Allah helps that person through his angels. This fact is mentioned in the Quran.
"Yea, - if ye remain firm, and act aright, even if the enemy should rush here on you in hot haste, your Lord would help you with five thousand angels Making a terrific onslaught.
surah al emran chaptor no 3 verse no 125
Remember ye implored the assistance of your Lord, and He answered you: "I will assist you with a thousand of the angels, ranks on ranks."
surah anfal chaptor no 8 verse no 9
Keep Me In Your Prayers