A Brief Description of the Question:
Sometimes certain people give an impression as if they are brain-washed. If Islam is the right religion, why do some people find peace in other religions?

The Answer:
Human is an entity exposed to test. In order for the test to be just and objective, the truth should be clarified to the reason, but it should not be forced into one single route. It is because of this wisdom of the test that different mechanisms, feelings and intuitions are created in humans. The bases of these mechanisms are intelligence, anger and appetite. These drives have different reflections. Some of these reflections, which appear on social, cultural, environmental, and psychological grounds, address the sublime pleasures of the spirit, while some address the abased pleasures of the soul.
Parallel to the dominance of these feelings, while some people are disturbed by hurting an ant, some take pleasure from killing people. While some people feel great pangs of conscience from harming others' property, life, and integrity in the least, some enjoy trespassing on others' integrity, property, and life.
The habits humans acquire with their own free will have a great role in these different inclinations. The hadith:“Human is created in a creation (fitrah) suitable to accept Islam. However, his/her parents make him/her Jewish, Christian or Zoroastrian.” points to the role of the habits acquired from the vicinity in time.
As is understood from these explanations we have briefly stated, just as everything that we take pleasure from is not necessarily a truth, so too everything that we don't take pleasure from is not necessarily a falsehood. There are thousands of people who take pleasure from smoking marijuana, drinking alcohol, smoking, murder, human trade and from adultery. Does it show the truth of what they do that they take pleasure from them?
It is known that the idolaters of Mecca fought wars and died for the sake of their religion of paganism. Can this attachment of to paganism be a proof of the truthfulness of this religion of paganism, to which they were attached in time through habits and traditions-though it was unreasonable?
If we reverse the same question; “if Christianity or Judaism is the right religion, why then billions of people find peace in the religion of Islam?
In history, hundreds of thousands of people from other religions have entered Islam by using their intelligence and knowledge, but there isn’t any single person who entered another religion from Islam by using his/her intelligence and knowledge. Some ignorant people are excepted. Today also many priests, philosophers, and scientists continue to enter Islam. However, we don't witness any scientist, imam, or scholar who is knowledgeable about Islam leave Islam and enter another religion.
In addition to this, there are hundreds of reasonable, scientific and objective proofs which show that the Qur'an is Allah's speech, that Prophet Muhammad (PBUH) is Allah's Messenger, and that Islam is the right religion.