RikaReh

"Preacher" is supremely gory. It is also heavy on making a joke out of religion - and it doesn't care WICH religion it is either. There's things going on that don't make any sense WHATSOEVER until four episodes later.
You keep on shaking your head and telling youself "what the hell" and then you keep on watching anyway, because it is weirdly addictive.

If you haven't read the books, it will take you a moment to figure out that the different story lines are sometimes decades apart. But that is the only thing that might confuse you for a moment, otherwise you're good to watch it without ever having read the books (or played the games). It'll take a while to get used to some of the cast choices, while others are nearly perfect.
All in all an enjoyable watch. It doesn't leave out the ugly, nasty parts or hides a single not-perfect character trait. Go watch it!

As a pilot, it did not convince me.
The female lead character fell into everything that happened WAY too easy. -OH, there's a demon possessing my friend? Alright, no problem! I can see lost souls? Sure, why not?-
A bit of a Mary-Sue, with no ACTUAL character in there.
And the sob-story for Constantine was convenient, but again - too easy. Especially too easy to get out of him.
As a rule, I give every new show I start five episodes, and THEN I decide if I stop or continue watching, and I'll do that with this one too, but so far it's not promising.