The theme of a piece of fiction is its view about life and how people behave, which should be expressed in a sentence with a subject, verb, and object. However, the theme of a fable is its moral and the theme of a parable is its teaching. The theme in literature is generally not intended to preach (for that is its purpose, which differs from theme), except in a work such as Everyman, which is a religious allegory, where its purpose is didactic, meaning it was written to teach a lesson about sin, forgiveness, and salvation. Thus, the themes in Everyman coincide with its purpose, which is to teach us moral lessons: if one falls into the “slough of despond,” for example, one must remember the goodness of God, pray, and continue to move forward in spite of the difficulties. Each time you become away of a key topic in Everyman, try to express it as a “moral” in the form of a sentence, for in that way you will more exactly identify its themes. Its very very broad theme would be that “Life consists of a journey to God, and humankind is weak and needs God’s grace in their journey to find Him.”
One theme is alienation and loneliness. Everyman discovers that when he faces death and God's judgment, he must do so alone.
Another theme is atonement and forgiveness. Everyman seeks atonement for his sins and then is given God's forgiveness for his sins.
Everyman also discovers that earthly friends and family will ultimately betray you because they are selfish. Everyman is forced to look for greater truths when he's abandoned by others.
Everyman isn't prepared to go with death to meet God, and he asks for extra time to get ready. He uses this time to look at how he's spent his life.
The importance of God and religion is also shown. Religion provides the way to get God's salvation.
It's believed that good deeds will get a person to heaven. Family, friends, or any earthly possessions aren't important.
Knowledge gives Everyman the help he needs to recognize and understand how he has sinned. This knowledge leads him to confession and salvation.
Sin is the main theme of the play. Sin causes man to stray from God, and he must renounce his sins in order to be saved.
For more details, go to the link below.
Simply put, the theme of the play is human nature and its spirituality.
The main character, Everyman, represents, as the name implies, every man and woman. The play expresses various moral and spiritual themes, all of which are largely Catholic in orientation, but is also applicable in general to other religions and beliefs.
Some of the broader topics which the play discussed is the theory of an afterlife, which is predetermined by one's behavior in the present life. This entailed a philosophy that (1) a person must "live for tomorrow" i.e., live so as to earn a good afterlife, so to speak; and (2) a person must therefore put spiritual over physical goodness, because one would not be able to take the latter into the afterlife with him/her.
As a whole, the play shows that Death is inevitable, but God is merciful, and thus Everyman should act accordingly.