In the portrayal of Christianity, I really enjoyed the CRUSADERS comics, which focus on two Christian missionaries who go on adventures all over the world to aid Christians. And each issue tends to focus on a single theme.
Sporadically published at 1 or 2 issues a year from 1974 to 1983, they have beautiful art, comparable to either Wrightson or Alcala in the early issues. I have the first 17 issues, and haven't seen the others not pictured.

CRUSADERS comics.

The first issue Christians smuggle microfilm of the Bible into Rumania to bring the Gospel to Christians there, where the Bible is banned, and Christians brutally suppressed. (A delicious "Godless commies" story, with lots of cold war espionage elements.)

Issue 2 focuses on Satanic cults and murders in Southern California, and abducted runaways.

Issue 3 centers on the racist black president in a former British-colonial black African nation.

Issue 4 deals with demonic possession in India.

Issue 5 deals with a Jewish-Christian scholar in Israel, and Bible end-time prophecy, the anti-Christ, and tribulation period.

Issue 6 focuses on a Hollywood director creating a film that perpetuates secularist anti-Christian myths, specifically on the subject of evolution.

Issue 7 (my favorite) is THE ARK, on the history and evidence of Noah's ark, and archaological digging on Mount Ararat in modern Turkey. With some fun subplots of Soviet Communists trying to stop them.

Beyond these, Jack Chick seems to have undergone a transformation, and the issues after these are focused on the Roman Catholic church as a false form of Christianity, with testimony of former Catholic priests. They are less well-illustrated and are far more text-heavy. Wonderful stuff though, if your tastes run toward conspiracy theory. But the art and storytelling in these latter issues is a bit dry and less engaging.
Issue 17, the last I have, focuses on Islam as creation of the Catholic church to expand their influence in the Arab world, that backfired and spun out of control.

You can view these issues and a few sample pages of each at Jack Chick's website, http://www.chick.com , as well as pages of the smaller Chick tracts.

Here's the specific page for the CRUSADERS titles:
http://www.chick.com/catalog/comiclist.asp#crusaders