Assalamu 'alaikum wa rahmatallahi wa barakatuh,
Although Tawheed is so vast and important that 5 points cannot do it justice. Still here are 5 things to remember about the importance of Tawheed, with the intent that they will result in a desire to learn more:
1. Tawheed differentiates between Muslim and Kafir: If there is any reason for us to study, understand and protect our Tawheed, this would definitely make the top. It is a requirement for being Muslim and its absense poses a very scary situation.
2. It is why we were created: "And I created not the Jinns and Men except that they should worship Me." [Qur'an 51:56]. Our purpose and reason for existence is to worship Allah SWT with utmost belief in His Oneness and worthiness to be worshipped.
3. It is the first tenet of Islam, which says a lot: Without this first and most fundamental principle, any and every other principle might fall short or waver.
4. This was the mission of all the prophets: All the messengers that were ever sent by Allah SWT had a sole purpose which was to spread and maintain Tawheed among the people the nations. How great a significance Tawheed has even historically that so many came with the same message.
5. It is our road map to Jannah, InshaAllah: It all starts with Tawheed,and ends with Tawheed. It is the most minimum and fundamental requirement for attaining Jannah InshaAllah. The alternative is one filled with terror and infinite agony. May Allah SWT protect us all.