what are key arguments for and against managing resistance to change

What is Change?
Why is change necessary?
What is the process of change?
Does the process of change need to be managed?
Should the change be managed?
What should be my role in change management?
Why is there always a resistance to change?
Is this resistance healthy?
Should this resistance be managed?
Is managing this resistance called change management?
Are there any benefits if this resistance?
What are the benefits of managing resistance to change?
How to manage resistance to change?

Definition of Change Management
Change management is an approach to transitioning individuals, teams, and organizations to a desired future state.[1]
Kotter, J. (July 12, 2011). "Change Management vs. Change Leadership -- What's the Difference?". Forbes online. Retrieved Oct 17, 2014. , http://www.forbes.com/sites/johnkotter/2011/07/12/change-management-vs-change-leadership-whats-the-difference/

In a project management context, change management may refer to a project management process wherein changes to the scope of a project are formally introduced and approved.[2]
Filicetti, John (August 20, 2007). "Project Management Dictionary". PM Hut. Retrieved 09/11/16. Check date values in: |accessdate= (help)

Resistance to change is the action taken by individuals and groups when they perceive that a change that is occurring as a threat to them.
Managing vs Leading Change
There is a difference that is very fundamental, and it’s very big, between what is known today as “change management” and what we have been calling for some time “change leadership.” The world basically uses change management, which is a set of processes and a set of tools and a set of mechanisms that are designed to make sure that when you do try to make some changes, A, it doesn’t get out of control, and B, the number of