What do you think is the practice that most sets Christianity apart from the non-Christian world?
Respect for human life? Not really. Religions such as Jainism have, if anything, an even more uncompromising prohibition against harming any living things.
Sexual morality? Again, there are religions—Orthodox Judaism and Islam immediately come to mind—that place an even higher premium on sexual purity than Christianity. If you doubt this, ask yourself when was the last time you saw a Christian woman in a burqa.
The answer to this question is forgiveness. No other belief system has the equivalent of forgiving your brother seventy times seven, i.e., every time—much less commands you to love your enemies, and bless those who persecute you. (Matthew 18:22, Matthew 5:44)