The creators of the Christian curriculum Sonlight developed Bookshark for this situation. It’s not going to include anything anti-faith in it. If you want to, you could even look at the Sonlight booklists and add in the explicitly Christian books (missionary biographies and Bible studies and whatnot) that were taken out to make it acceptable for charter schools.
I would think the big question would be what other reporting or compliance requirements go along with the choice to file as a charter school and if they match what you would have done anyway. Would you have to keep portfolios or have home visits? The people who are usually stressed about these things are the ones who feel there is a gap between what they are teaching and what he state wants them to teach. If you are teaching standard science and history, and don’t have any kooky Fundamentalist ideas, like “girls don’t need to learn math because they’ll never work outside the home,” then you don’t have anything to worry about. If the reporting requirements aren’t much different than for private schools then I don’t see how getting to spend free money on secular curriculum is such a bad thing. No one can stop you from buying Christian resources with your own money and teaching whatever additional topics you would like to teach in your own home. I was a public school teacher and have a lot of public school teachers in my immediate family and circle of friends, so my default view is that educators really do want what is best for kids and some degree of guidance by the state and oversight of homeschooling is healthy. But there is quite a bit of distrust in some homeschooling communities who see educators and the state education system as an arm of the evil, liberal, godless state. I was homeschooled as a child. My dad was a public school teacher. My parents had a great relationship with the local school officials and worked quite cooperatively with them until we went to school in middle school.
Some people simply aren’t confident enough in their own beliefs to add in their Christian worldview. They need a curriculum to spell it out for them. My personal opinion is that a lot of the “Christian history” programs incorporate some pretty distasteful dominionist theology (which I find racist) into American history and they often use dates for ancient history that are non-standard (to fit their flood geology). Mystery of History, which is used in many Christian homeschool programs does this. (We discussed that some here: Biblical vs. Secular approach to education: What's the difference? - #8 by Christy)
And then most explicitly Christian science programs are militantly anti-evolution.