Christian flag
Christian flag lapel pins are also incredibly common, and features (as the name implies) the flag that represents the Christian religion. Currently, that flag has a white field with a blue canton, and within that blue canton is a red cross ( with the color red symbolizing the bloodshed by Jesus).
The Christian flag is a universalist flag designed in the early 20th century and represents the entire Christianity and Christianity. Since its adoption by the Federal Church Council in 1942, it has been adopted by many Christian traditions, including Anglican, Baptist, Mennonite, Methodist, Moravian, Lutheran, Presbyterian, Kui Grams, reforms, etc.