To my knowledge, all my known ancestors practiced Christianity. They belonged to a wide variety of denominations, however. On my 3 Dutch sides, all but a handful left the Roman Catholic Church between 1550 and 1600. In most cases their church buildings and property were automatically turned over to the Reformed Church in 1572 (Noord-Holland), the 1580's (Friesland) and 1596 (Groningen), and everyone became Reformed by default. Some, of course, made sincere changes of belief; others "went with the flow". A few became Lutheran in the 1570's and then Reformed around 1620 - all by decrees by the princes, dukes and counts (Overijssel). In one case, a Catholic boy married a Reformed girl around 1650. They tried the Reformed Church for 10 years, then joined the Catholic church. Their oldest son, baptized Reformed, remained in the Reformed Church but remained friendly with Catholic family and friends.
There were also some ancestors who became Anabaptists (Mennonites) in the mid 1500's. Gradually they all became Reformed - some before 1620 and some after that. In one town (Giethoorn, Overijssel), most of my Mennonite ancestors moved to Friesland between 1770 and 1800 and joined Reformed churches there.
By 1810, all my Dutch ancestors had joined the Reformed Church. Then in the 1840's many of them broke away from a liberalizing Reformed denomination and formed a new, more conservative Reformed Church as time went on. In one town, there were 3 newly formed conservative congregations. The most interesting of the 3 was a community called the Mazereeuwers, after their founder Jan Mazereeuw. They basically held to almost all the tenets of Reformed faith, but they did away with all formality. No baptisms, no Lord's Supper (Eucharist), no church building, not even a planned sermon. Everything was casual. Most people called them a sect. They did read sermons written by Mazereeuw when he wasn't there; otherwise he just talked informally. He had an obsession with the book of Daniel. Oh yes, it was said that Jan Mazereeuw was the prophet of God and that he would never die. When he died in 1855, members slowly fell away and joined the main conservative Reformed Church.
On my Colonial American side, my ancestors were an interesting mish-mash of Puritan, Quaker, Baptist and anything else Protestant in the neighborhood. One of my immigrant ancestors was Puritan when some Quakers came to the colonies and were persecuted for their faith. He wasn't going to put up with that, no sir! So he decided to show the authorities a thing or two - he became a Quaker himself! And a rather obnoxious one, if I read the stories correctly. He got fined so many times for flouting the law as a Quaker that he couldn't afford to pay them. His brother found an old obscure English law that allowed him to declare himself dead. So his first house went to his older children, and when he really did die several decades later his younger children got the new house.