Explain the impact slave revolts had on attitudes toward slavery both for and against?
The slave revolts in what would become Haiti created the second independent republic in the Americas and created panic across the slaveholding world of the Americas. It undermined slavery in the Carribean and with slave revolts in places like Jamaica undermined slavery in the British Empire.
Slave revolts in the U.S. such as the rebellion of Nat Turner, tended to harden positions among whites in defense of slavery, and lead to suppression of abolitionist expression in the South, and in the North it dissuaded some against abolition, as such revolts played into the hands of slave apologists about the natural "savagery" of blacks, while those who were militant in the abollition movement regarded such revolts as the natural instincts of humans yearning to be free.
However while slaves seeking to runaway invoked sympathy toward abolition, slave violence while understandable from the perspective of today, tended to horrify whites and could be manipulated to bring disrepute to abolitionist efforts in the white population. Essentially the argument was that the end of slavery would bring about racial violence and race war.
Militias were much more organized in the South than the North, for fear of slave revolts. This is particularly the case in states that had a large black minority or in the case of South Carolina, a black majority.
Black abolitionists, particularly those who had spent some time in slavery had a different perspective.
I would have to argue that the major slave revolts had a much more negative impact on general attitudes towards slavery. Abolition really didn't grow as a movement until the 1840s and 50s, so from the Stono Rebellion to the uprisings with Gabriel Prosser and Nat Turner, there was relatively little abolitionist sentiment in the country.
So what the rebellions actually did (none were successful) was scare whites, primarily in the South, and lead to a series of legal reforms and slave codes designed to make revolts more difficult. This included making it more difficult to free your slaves through manumission (in your will when you died), and illegal to educate them or to allow black preachers (Nat Turner was one).
While these were extreme reactions, very few people in the South or elsewhere viewed the slave revolts as evidence that slavery was un-Christian, and they largely thought of the uprisings themselves as brutal rather than the daily oppressions of slavery being that way.