Angels and Satan

I had a conversation with a Christian recently (not sure of her denomination) who has two beliefs for which I can't find a scriptural basis. One is that angels are sent by God, but we must ask for their help before they will intervene in our lives - almost as though they are just standing by, waiting to be called up by us. The other is that by blessing a building and writing a series of numbers and letters above an entryway with chalk (which she does annually) she can "keep the Devil out." Are these some kind of distortion of Scripture, or am I just uninformed? Thank you.

Angels are “ministering spirits sent to serve those who will inherit salvation” (Hebrews 1:14). While God can certainly direct his holy angels to action in our lives as an answer to our prayers, there is nothing in the Bible that says “we must ask for their help before they will intervene in our lives.” And aren’t we glad that is the case? If we always had to ask for their help, would we remember to ask? Would we be timely in remembering to ask for help before danger struck? We enjoy many blessings of God even before we ask for them (Isaiah 65:24). God tells us he is the one who orchestrates his holy angels into action for the good of his children (Psalm 91:11).

Regarding your second question, the letter and number writing can easily come across to someone as a superstitious practice. How do we “keep the devil out” of our lives? We cannot eliminate him entirely from our earthly lives, but we do have this instruction and promise: “Resist the devil, and he will flee from you” (James 4:7). We resist Satan with the spiritual armament God provides (Ephesians 6:10-18). The great Reformation hymn reminds us how powerful that weaponry is in the battle against Satan: “One little word can fell him” (Christian Worship 200:3).