Not much has changed over theyears, and my guess is that many readers would give the same answer. Resistance is any force that slows or stops movement. We all resist things that go against our interests. Life would be impossible without this protective mechanism.
People resist in response to something.
I have identified three levels of resistance. It is the world of thinking and rational action. Level 1 is the world of presentations, diagrams, and logical arguments. Level 1 may come from lack of information, disagreement with the idea itself, lack of exposure, or confusion. Many make the mistake of treating all resistance as if it were Level 1.