I believe in angels as ministering spirits. However, I don’t worship them. I only worship God.
“And the angel answering said unto him, I am Gabriel, that stand in the presence of God; and am sent to speak unto thee, and to shew thee these glad tidings.” Luke 1:19
Since angels are sent by God, we can surely thank them for doing their duty (as opposed to the angels who didn’t - ref. the Epistle of Jude).