When first attempting to change an organization’s culture, it is most important to focus on:

People resist change when they don’t understand why it's happening. Clearly communicating the rationale builds buy-in and motivation, especially in deeply rooted cultural shifts.

Extract from HRCI-aligned HR knowledge (Leadership and Strategy):

SPHR best practices in organizational change stress that “the foundation of successful culture change lies in articulating the business case.” Justifying the shift ensures internal alignment and smooth execution.