How to Get Excommunicated 

As state before, an Amish teenager has a certain time in their life that allowed for experimentation with technology, drinking, and their religion. If they choose to come back to the Amish after that, they must adhere to the rules. Sometimes, they don't. If an Amish person is caught owning a computer or phone, drinking alcohol, or refusing to attend and take part in church services, they can risk excommunication. 

Against Evangelism

Although the Amish are recognized as Christians, they do not engage in the same activities that Christians do. They are against the idea of missionary work and evangelism to gain more converts to the faith. The Amish community believes that religion is a choice and not something you're born into. At the same time, they don't believe that trying to convert people is a natural way of bringing them closer to God.