Religion creates controversy(sp) which inturn creates discussion. Christianity is greatly disputed. On one hand you have non-christians trying to disprove while Christians try to prove. On the other hand you have Christians disputing among themselves. This wide range of different people fighting to prove, disprove, or adjust creates opportunity. Christianity probably outways other faiths in this area because of the many 'branches' of the faith create discord in the faith.
And some people just like to argue. Few subjects excite as much emotion.
Add to this that faith is an issue that creates an intense need to share. Christianity promotes 'preaching the good word'. No matter what 'branch' you are a part of. Ofcourse once you start preaching the good word you enter into the realm of the first point I made.
Do non-christian natured material have a chance? Yes but maybe we need to promote them a little differently. Maybe to create interest in broader subjects we hubbers need to write on broader subjects and encourage our fans not to just leave encouraging comments but respond with hubs. Maybe even write hubs that are posted in conjuntion with a question to broden the subject you started. Or end your hubs with a challenge (friendly ones) to encourage more interaction. Connect with like minded hubbers, take a subject divide it up amongst all of, and give yourselves a specific deadline to post them all on the same day. Several articles posted at once by several people may encourage others to contemplate the subject more.For example-Say with gun control three people come together and each choose a different root cause to elaborate on:Poverty, population explosion, number of weapons available.Then post a question at the same time: Which of these causes discussed in these hubs do you feel has the greatest factor on gun violence? Or do you feel there is a different root reason.
Just some suggestions to create interest. And interest is what we need to create.