The idea of 'purpose' is a human invention. They invented it because they observed the universe and discovered consistent cause and effect relationships. It is not necessarily the case the outside the universe or prior to the universe the laws cause and effect. Cause and effect may simply be features within the universe.

It is counter intutive to think that whatever event created time and space had the 'motive' to create time and space. For what we think of as a 'motive' to exist, time and space must first exist, without these things consideration is impossible. Where and when does the consideration take place, where and when does the causer exist? It cannot be anyplace or anytime.