Study after study have shown that people will only be motivated to change when two conditions are met: they need to believe the change is good for them, and they have to choose to change themselves. Pressuring someone to change reduced motivation, resulting in greater failure rates.
For a long time psychologists successfully applied this rule when dealing with many types of addictions and problematic behavior (even with kids), helping clients develop their own motivations rather than shaming them to change. Then executive coaches picked up on this technique and tried it in the corporate world, and they had less success.
The catch? They got the other part wrong: that small detail of helping people understand why the change was good for them.
So next time your change program is met with resistance, rather than pushing harder, take a step back. Then, help those you're trying to change understand the value of what you're doing, and allow them to choose to go along on the journey. Show them, don't tell them.
And if you can't do that, maybe it's the change program itself that needs to change.