He promised a kaafir that he would go to the church with him
Question

                Is breaking promise with non-muslim permitted by Allah SWT? I happened to
have a conversation with a non-muslim man who is a Christian at my work.
He is about 45 years old and I am 20. I always try to keep myself behave
politely at this new work environment at which I will be working for the
next 5 years at the same place, Insya Allah. Apparently, this man has been
trying to influence me with Christianity in several different ways. First,
he acts in a nice way and a couple days ago invited me to talk about
      Al-Qur'an and Bible. He said that in the Bible, Ibrahim was asked by Sarah
      (his wife) to sleep with their servant to have a baby, Isaac.
      Astaghfirullah! I responded that it was not true! Second, he asked me to
      bring Al-Qur'an. He said the reason was because he heard so many stories
      that are quite similar between Al-Qur'an and Bible. Third, he asked me if
      I would like to go to church sometimes just to see how it looks like when
      people pray. At that moment, I was thinking that there was nothing wrong
      to go to church as long as I do not participate in any ritual ceremony or
      activity. I said, "Sure..." and he quickly asked when would be
      the good time for me to go. After I thought for a second, I said,
      "Why and what is the purpose for me to go to church while I even
      sometimes cannot go to pray at the mosque or musholla due to my
      work?" I pray at my workplace because there is no mosque or musholla
      nearby my office. He said that it is just to know other people religion
      and not to converting or anything.
      On my way home, I was thinking that this man is slick. He seems a friendly
      guy but behind that tries to get me to his believe to a minor. As a
      muslim, I believe in Allah and He is the one who can help me. Allah knows
      best what I think and feel
Praise be to Allah.We
      put this question to Shaykh ‘Abd-Allaah ibn Jibreen (may Allaah preserve
      him), who answered as follows:
It is not permissible
      for him to go to the church, because this implies respecting and
      venerating it, and exposes him to developing a liking for Shirk and its
      followers. He has to break this promise and explain this ruling to the
      kaafir so that he will understand why the Muslim broke his promise. And
      Allaah knows best.