Mateen Charbonneau, Sheikh Mateen Joshua Charbonneau achieved a certificate from Harvard University in Islamic Studies. He undertook Howza classes under esteemed scholars since 2013 and has been teaching at Imam Mahdi... Answered 1 year ago

A Kaafir is someone who is ungrateful. This term is used for disbelievers because of all of the things Allah has given them they are ungrateful to Him and deny Him.