What is the ruling on entering Christian chat rooms with the intention of refuting misconceptions related to Islam, without disclosing one's Islamic identity, and is what the questioner did considered haram?

Inviting people to Islam is a great endeavor, but it carries risks for a Muslim with limited knowledge, as doubts might creep into their heart. Therefore, one must avoid arguing with those who propagate doubts. They can be referred to specialized websites. Lying is forbidden, even if intended for the purpose of da'wah (inviting to Islam). Instead, one can use ma'areed (allusive or ambiguous statements), especially if they can speak to you and discuss their reasons for not embracing Islam.