In an effort to win souls, a street preacher must convince two boys to walk the literal narrow and difficult path to salvation.

Hi Assaf,
is this closer to what you are aiming for?

In an effort to increase his disciples, an evangelist preacher must convince two boys to walk the literal narrow and difficult path to salvation.

Now, how else can you say this? "walk the literal narrow and difficult path to salvation"

re-write and we will see it then.