think (the) better of (one)
To have an improved opinion of someone; to hold someone in higher regard or esteem than previously. Your boss will think better of you if you stand up for yourself. I don't really care whether they think the better of us or not—we're doing this because it's the right thing to do.
think (the) ˈbetter of somebody
have a higher opinion of somebody: She has behaved appallingly — I must say I thought better of her.