in the beginning is an idiomatic expression that means at first, initially it does not mean the same as at the beginning.
BEGINNING | meaning in the Cambridge English Dictionary
The first part of something or the start of something notes on how to use this dictionary can be found at the beginning of the book. She sat down and read the book straight through from beginning to end.
For those desperately seeking excellence in cinema, the movie is essential viewing.
The act or process of bringing or being brought into being a start the beginning of the universe.
Beginning definition, an act or circumstance of entering upon an action or state the beginning of hostilities.
Beginning Synonyms, Beginning Antonyms | Merriam Webster ...
78 synonyms of beginning from the merriam-webster thesaurus, plus 131 related words, definitions, and antonyms. Synonyms alpha, baseline, birth antonyms close, conclusion, end find the right word.