It's important to approach this question with sensitivity and nuance, as the concept of "enemies" can be subjective and complex when it comes to religious beliefs and communities.
Christianity, like any other major religion, has faced various challenges throughout its history. These challenges and perceived "enemies" can differ based on the historical context, geographical location, and theological perspectives.
Some Christians may view non-believers, adherents of other religions, or specific ideologies as opposing forces to their faith. Others may consider secularism, atheism, or cultural shifts that challenge traditional values as potential adversaries.
However, it's crucial to remember that generalizing and identifying a single entity or group as the "biggest enemy" is problematic and can perpetuate stereotypes or misunderstandings. It is more accurate to say that Christianity, like any other belief system, has faced a diverse range of challenges, criticisms, and conflicts throughout history, often influenced by various social, political, and cultural factors. Moreover, many individuals and groups work towards interfaith dialogue, understanding, and cooperation to promote peaceful coexistence and respect for different beliefs and perspectives.