Paul McCartney wrote this song. He was inspired by his mother, Maria, who died when he was 14. Many people thought that “Mother Mary” was a biblical reference when they heard it.
Since Let It Be was the Beatles’ last album, he made an appropriate statement about leaving problems behind and moving on in life. The album had to convey a completely different message. It was going to be called “Get Back” and they were going to record it in front of an audience on live television, with another television special that showed them practicing the songs in the studio. The Beatles would go back to their roots and play live music without embellishments instead of fighting in the studio as they did for The White Album. When they started putting together the album, it became clear that the project would not work and George Harrison left the sessions. When he returned, they abandoned the idea live and decided to use the TV footage as his last film. While the film was being edited, The Beatles recorded and released Abbey Road, and then split up. Finally, Phil Spector received the tapes and was asked to produce the album, which was published months after the separation of The Beatles. By then, it was clear that “Let it Be” would be a better name than “Get Back”.
McCartney had a dream one night when he was paranoid and anxious. He saw his mother who had been dead for ten years or so; she came to him in his time of anguish, uttering words of wisdom. This brought him much peace when he needed it. It was this sweet dream that made him start writing the song.