Muslims act upon specific religious laws and regulation. For example, they only eat meat from animals that has been slaughtered in the Islamic fashion. Then what makes Muslims better than the people of other faiths? Why does God prefer Muslims to the followers of other religions?
The fact that Muslims do not eat meat of animals which are not slaughtered in the Islamic fashion is an Islamic regulation that entails some benefits and rationales. However, this factor does not allow Muslims to consider themselves better than the others; because even if a Muslim slaughters an animal and does not act according to the specified prescription, it is not permissible to eat that meat. So, the conditions of Islamic slaughtering, including the person being a Muslim and other conditions are not criteria for superiority; in fact, the value and superiority in Islam is based on faith and good deeds. There might be some non-Muslims (monotheists of course) who sincerely search for truth, even though they fail to achieve it, and practice what they have learned earnestly; such people are indeed very close to Allah (SWT). On the other hand, there might be some people who only bear the name of Muslim while they are hypocrites in reality; these people will be punished in the Hereafter.