They Don’t Baptize Babies
In Christianity and Islam, they baptize newborn babies under the auspices that only then can they be recognized as a Christian or Muslim by God. But the Amish have a different belief system that sees them baptizing children when they are much older.
They perform what is called a believer’s baptism when a child has entered adulthood, i.e., puberty. This is because they believe a child can’t be meaningfully baptized, so they wait until adulthood when a person can officially profess their commitment to Christian and Amish ways. This belief is initially attributed to the Anabaptist Christian movement.