"Where does Islam condemn slavery? The koran says it's ok as long as they're 'infidels'"
Where does the New or Old Testament forbid slavery? May I remind you that all major religions at one point or another condoned Slavery. It is also true, however, that the Quran established an entirely new ethic on the issue of slavery and ISIS’s selective use of certain Quranic texts to justify contemporary chattel slavery ignores this fact.
First, consistent with the new ethic, the emphasis in all of the revelations on slavery is on the emancipation of slaves, not on their capture or the continuation of the institution of slavery. (See, for example, verses 2:177, 4:25, 4:92, 5:89, 14:31, 24:33, 58:3, 90:1-12.)
There is not one single verse suggesting that the practice should continue. Further, the Quran makes no mention of slave-markets or slave-trading and it repeatedly exhorts believers to free their slaves as an exemplification of their piety and belief in God.
Perhaps the best example of this emancipatory ethic is chapter 90, which is explicitly addressed to the Prophet Muhammad. It posits that there are two roads one can take in life and that the “high road” is the one that leads the righteous human being to free slaves.
The Prophet followed this exhortation, exhibiting a great solicitude for the material and spiritual condition of the slaves in the society around him. His example inspired his companions to emancipate thousands of slaves and, in an oft-quoted statement, he remarked that he would meet the man who “sells a free man as a slave and devours his price” on Judgment Day.
This is an explicit condemnation of trafficking in free human beings.
It is true that there are reported examples from the Prophet’s life that describe him as giving and receiving slaves and he even used slavery as a tool of conquest in war.
He freed all of his individually owned slaves and the wartime circumstances in those reports were very unique, involving specific people who engaged in war or treachery against him.
There is only one Quranic verse, 47:4, that authorizes capture of prisoners of war and it does not permit slavery, ordering military commanders to either free the prisoners gratis or hold them for ransom.
Enslaving a prisoner of war is therefore arguably illegal and certainly enslaving a non-combatant is likewise an Islamic crime.
http://thecnnfreedomproject.blogs.cnn.com/2014/11/05/isis-says-islam-justifies-slavery-what-does-islamic-law-say/
Part 1