So the pressure to believe is usually the pressure to believe in whichever religion into which a person is born and these people pressuring others are ignorant of the fact they, themselves, never chose a religion. They were born into it.
It's pretty obvious that most children adopt the religion of their parents. Thus, a particular religion continues to be passed down through the family generations in most cases. It's part of the family DNA, if not the biological DNA.
Parents, peers, family all help with the indoctrination of a child into the same religion that has always been passed down through their family and their local community. Local community had a lot more impact back when we were a more agrarian and rural society.
The fervent believers in Christianity would be fervent believers in Islam if they were born in an country where Islam is the predominate religion and their family was Muslim. They would be Jewish if they were born into a Jewish family. They would be fervent believers of Hinduism if they were born into an Indian family that practices Hinduism and so on with other religions.
It so pains me to hear adults continuing to tell children they're going to burn in hell for sin and not believing in Jesus/God.