Motivating vs. Lecturing

I had a couple come in together to talk to me about lecturing them. I was wondering how does a trainer motivate their clients to complete challenges on their own without feeling like their trainer is lecturing them? I felt awful that they had a terrible week because they wanted to be defiant and do exactly the opposite of what I was saying. They felt I was just telling them that they were wrong and they had to do things my way. That wasn't my intention to make them feel bad for being themselves. I felt, on the other hand, that I was giving them ideas for how to plan out their week. Am I doing something wrong?