“how could John recognize either Mary or Jesus if his soul didn’t exist and know either of them before? “
He had a soul in the womb. His soul was stirred. I doubt he “recognized” Jesus from a previous encounter. That would imply some pretty serious discussions went on when they were babies.
Why was his soul stirred?
The poet William Wordsworth (1770–1850) said it best I think:
Our birth is but a sleep and a forgetting:
The Soul that rises with us, our life’s Star,
Hath had elsewhere its setting,
And cometh from afar:
Not in entire forgetfulness,
And not in utter nakedness,
But trailing clouds of glory do we come
From God, who is our home:
Heaven lies about us in our infancy!