For historical reasons. The churches used to be much more politically active in the deep past and collected their dues directly. There also wasn’t any sort of s

For historical reasons. The churches used to be much more politically active in the deep past and collected their dues directly. There also wasn’t any sort of safety net provided by the lords of the land, but churches provides some. This has evolved to a system where the church largely stays out of politics and has no direct or official influence, but gets money from the state. This is also helpful for the state to influence the church, for example like with the acceptance of gay marriage.