'In the beginning' and 'At last'

Hello! How do ya feel?

Have a look at this sentence:

‘AT FIRST he opposed the marriage, but IN THE END
he gave his consent’

Could I use ‘In the beginning’ instead of ‘At first’
and ‘at last’ instead of ‘in the end’?

Do they mean the same?

If not, could you give some examples with
‘In the beginning’ and ‘At last’?

Thanks a lot!


Yes, your substitutions would be fine, Jesus.