In modern times, there is a new threat. It is a development of the Islamic State. In those places in the world, where it become more and more heard, exist other religions besides Islam. But their followers are atiny minority compared with the followers of Islam prevailing there. The presence of other religions, especially Christianity, is seriously threatened. Virtually every day media communicate shocking information on cases of cruelty of Islamic State militants, carried out on people belonging to the religious minorities, especially on Christians. But yet, international documents guarantee the religious security of every human being. Each man, also that belonging to a religious minority, has guaranteed the right to religious freedom. However, can he feel safe? Do Christians living in the Middle East, being the religious minority, can feel safe? Do Europeans in the near future will not worry about their religious and national security? Whether due the mass, uncontrolled inflows of immigrants from Afghanistan, Syria, Iraq and other countries in the area of influence of the Islamic State, religious and national security of Poles will not be endangered? The order of the security risks indicated in the title is not accidental. In the event of non-compliance with international rules by supporters of the Islamic State, the religious security of the religious minorities in the Middle East will will not be guaranteed. Whereas, in the case of Europe, non-compliance with international rules, not respecting by immigrants the existing culture and traditions, may lead to a sense of religious insecurity among Europeans. If the country can not guarantee the religious security of its citizens, there will appear cases of abuses against people belonging to other religions. Such situations beyond the control of the state institutions can induce a threat to national security which is a matter of time.