Playing Devil's Advocate

I think it's fairly obvious what the general meaning of this phrase is. But, it will be fun learning more about it nonetheless. :)
Here are some different meanings that are interesting:

1. opponent for the sake of it, somebody who argues about something merely to provoke discussion.

2. Catholic official opposing canonization: a Roman Catholic official appointed to argue against the canonization or beatification of a candidate.

3. One who argues against a cause or position, not as a committed opponent but simply for the sake of argument or to determine the validity of the cause or position.

Origin: 

Originally, a Devil's Advocate (from the Latin Advocatus Diaboli) was a Roman Catholic church official who had been appointed to argue the case against a proposed canonisation or beatification of a candidate for sainthood. (The supporter was, until 1983, called Advocatus Dei - 'God's Advocate'.) The Devil's Advocate's formal title is Promoter of the Faith (Promotor Fidei), which isn't quite as sinister.

Taken from the Latin advocatus diaboli (devil's advocate). The Roman Catholic Church had a person appointed as the devil's advocate to argue against elevating someone to sainthood. The person arguing for the person was known as God's advocate

2 Corinthians 5:1-8 "For we know that if our earthly house, this tent, is destroyed, we have a building from God, a house not made with hands, eternal in the heavens. For in this we groan, earnestly desiring to be clothed with our habitation which is from heaven, if indeed, having been clothed, we shall not be found naked. For we who are in this tent groan, being burdened, not because we want to be unclothed, but further clothed, that mortality may be swallowed up by life. Now He who has prepared us for this very thing is God, who also has given us the Spirit as a guarantee. So we are always confident, knowing that while we are at home in the body we are absent from the Lord. For we walk by faith, not by sight. We are confident, yes, well pleased rather to be absent from the body and to be present with the Lord."

http://www.answers.com/topic/devil-s-advocate

http://www.bing.com/Dictionary/search?q=define+devils+advocate&FORM=DTPDIA&qpvt=devil%27s+advocate+meaning

http://www.theanswerbank.co.uk/Phrases-and-Sayings/article/where-did-the-term-devils-advocate-come-from/
http://www.webanswers.com/misc/where-why-did-the-term-devil-s-advocate-come-into-use-e48a38