in name only

nominally, formally; not actual, only by terminology

The President is the head of the country in name only. Congress makes the law.

in name only by milan stejskal October 11, 2007

Christian in name only 

When you push pro-Christian values, but ignore everything Jesus said about helping your sister or brother and loving everyone unconditionally.

Susan: Bill is such a strong Christian.

John: Hardly. Bill is a card carrying member of the KKK. He's more of a Christian in name only sort of guy.

Christian in name only by The Fratriarch October 2, 2021