This document provides an introduction to a course on Islamic theology (tawheed) taught in English for adults. It contains extracts from lessons which define important concepts in Islam such as the shahadah and important supplications. It emphasizes that outward practices alone do not define whether an act is shirk (polytheism) or part of true Islamic belief - the intentions and beliefs in one's heart are most important. The document warns against hasty judgments and accusations of kufr (disbelief) against other Muslims. Overall it aims to instruct students on correct Islamic beliefs and practices according to Quran and hadith.