A student is intimidated by a certain skill or project, and so the teacher says to the student:
"Don't worry. You can do it. It's easy."
So the student takes your word for it. They make an attempt. And they fail.
My fear is that the student heard the teacher say the task was easy but they failed, and now they are left thinking that they must by dumb. Afterall, they couldn't even do something that was suppose to be easy!
My suggestion: there's no need to say something is easy. Let the student decide for themselves. We gain very little by saying something is easy - if the kid succeeds, it certainly won't be because you said it was easy, and if they fail, you saying it was easy will only complicate things.
For best results, encourage students, guide students but don't sell something as easy (even if you think it is).