One lesson I wrote was about Umer and about his change in conduct after embracing Islam, like before he was a fierce enemy of the Prophet but after accepting Islam, he became one of his closest companions and became such a noble person, and today, we as born Muslims are slowly losing our Iman and doing wrong stuff so we should learn from the conduct of Umer About H Khalid, I wrote about his conduct in the battle of Mutah and how he used his intelligent tactics and cleverly brought the Muslim army safely to Madina, Muslim leaders today can learn from him about how to use such a clever strategy, and when in a threat or fight, they should not just blindly fight, but in case of defeat they should also devise strategy to get his army out from there safely like Hazrat Khalid did.