Other Presbyterians were concerned that revivalism presented a threat to church order. In particular, the practice of itinerant preaching across presbytery boundaries and the tendency of revivalists to doubt the conversion experiences of other ministers caused controversy between supporters of revivalism, known as the "New Side", and their conservative opponents, known as the "Old Side". While the Old Side and New Side disagreed over the possibility of immediate assurance of salvation, the controversy was not primarily theological. Both sides believed in justification by faith, predestination, and that regeneration occurred in stages.