So back in the 1930s in the United States, there was a group of people who were very concerned about making sure that the country followed what they believed were religious values based on Christianity. They formed a political party, which means they wanted to be a group that could make decisions and influence the government based on their beliefs.
They called themselves the Christian Party because they believed that Christianity should guide everything in society, including politics. They wanted to make sure that laws and policies aligned with what they believed were biblical principles.
So, for example, they might be against things like drinking alcohol, because some Christians believe that drinking is bad. They might also be against things like gambling or sexual behavior outside of marriage, because they believe those things are not in line with God's teachings.
The Christian Party didn't end up having a big impact on national politics, but it did show how important religion was to some people when it came to making decisions about how society should work.