Abolition in its infancy took a very religious tone. It was introduced in large part thanks to Northern congregations like the Quakers and Presbyterian's and popularized in large part by secular groups. Famous abolitionist William Lloyd Garrison was inspired by Rev. John Rankin's "Letters on Slavery" and Garrison got famous writing for Quaker Benjamin Lundy's "Genius of Universal Emancipation." Garrison himself was a deist at best. Though raised by a religious mother, he himself took a very secular tone in his own abolitionist newspaper "The Liberator." In regards to his own thoughts on religious doctrine I'd refer you to a quote of his to a women's suffrage convention in 1854:

"The human mind is greater than any book. The mind sits in judgment on every book. If there be truth in the book, we take it; if error, we discard it. Why refer this to the Bible? In this country, the Bible has been used to support slavery and capital punishment; while in the old countries, it has been quoted to sustain all manner of tyranny and persecution. All reforms are anti-Bible.”

This echoes the frustration of many people of the times regarding religion's inability to neither completely support or wholly oppose slavery. In the 20 years prior to the civil war the Baptists, Methodists, and Presbyterian's had each found themselves divided into Northern and Southern denominations that arose in large part over the question of slavery. The struggle over slavery opened a lot of people's eyes to the many contradictions associated with strict interpretation of religious text. It played a significant role in secularizing free thinking individuals like Garrison.

Now with that being said, and in taking closer look at your original question I would advise anyone studying this time period to recognize the importance of changing economic situations in both the North and the South from 1790-1860. Industrialization saw slaves being replaced by low wage earning white immigrants as the preferred form of cheap labor in the factories of the North. Whereas in the South the introduction of the cotton gin and resulting cotton explosion placed further economic reliance on slavery. This shift in the North allowed it to truly distance itself from slavery enough for the roots of abolitionist work to really take hold. If this hadn't happened there would have likely been too much opposition for it to ever build momentum. Because of this I would still consider economic factors to be the greatest driving force in the growth of abolitionism.