'Everything' is a singular indefinite pronoun. 'All things' is a plural noun phrase. Judging by this fact, let's go through their similarities and differences.
'Everything' is considered one word and it is an indefinite pronoun. But what about its alternate spelling with space between the two parts? Is it also correct?
'Anything' and 'everything' are both pronouns that are used to refer to something. They have fairly similar spelling and structure, but what's their difference?