In thematic education, leaders and cadres need to deepen their theoretical armed forces and maintain theoretical clarity. The most important thing is to master the critical skill of Marxism. If a nation wants to stand at the pinnacle of science, it cannot be without theoretical thinking for a moment. In a certain sense, the depth of mastering Marxist theory determines the degree of political sensitivity, the breadth of thinking horizon, and the height of ideological realm. The more firmly the leading cadres have a grasp of Marxism, the higher their political standing, the stronger their political judgment, comprehension, and execution. They are more proactive in observing the current situation, planning development, and preventing and resolving risks. On the contrary, once the ability to judge a family is not strong enough, it is easy to be eroded by various erroneous ideas and unhealthy tendencies. There is truth in the heart, and the right path at the feet. Marxism is not a dogma but a guide to action, an open theory that develops with the development of practice. At present, mastering the critical skill of Marxism is to use the latest achievements of Marxism's sinicization and modernization to unify thoughts, will, and actions. (Outlook New Era Network)