Oftentimes the church proves to be a barrier between the target and hell. However, church is not necessarily a bad activity as long as your subject deals with it in the right way. In order to loosen the enemy'y grip on your subject, use the idiosyncrasies of other churchgoers to make the institutions seem ridiculous. Alternatively, you can argue against the church with jargon, which will also make church seem ridiculous.
Church can be used in many other ways for the advantage of our father below. For instance, you could slyly convince your target that anything that bothers or irritates him/her is sinful. This will render any prayers harmless and destroy any real ideas your subject has about the enemy.
All humans have desires, all of which you can exploit. The most reoccurring and successfully exploited desire is the desire for sex. You can use this desire most effectively by perverting the human conception of love. By making your subject think his sexual pleasures result from love, will mask the sin which the action contains. The less aware the subject is of his sin the better chance you have of capturing the subject's soul.
This is only a sort list of some common points of attack. The most effective points of attack will most likely be unique to your subject. The key is to be able to identify and exploit the weaknesses on your own.