Amish welcome converts to varying degrees
Amish groups vary as to how open they are to accepting outsiders. Generally, they tend to discourage the idea. One reason is that Amish realize how difficult it can be for someone not raised in the culture to join it. The sacrifices–giving up technology, dressing plain, adopting a non-individualistic outlook–are usually too great.
However, some non-Amish do successfully make the journey to becoming Amish. Some Amish communities, and churches, are notably more open to outside attempts to join.
New Order Amish, for example, tend to be a bit more evangelical in this sense. New Order Amish also often preach at least part of church services in English when non-PA Dutch speakers are present. Certain settlements have a reputation for being more accessible to outsiders as well.
Read more on joining the Amish.
Photo credit: mcclouds