Don't Use Necromancy, but It Never Works

The catechism of the catholic church states in paragraph 21 16, all forms of divination are to be rejected. So don't try to summon spirits, whether human or non human, for purposes of getting information out of them. How does that relate to asking the saints for their intercession? They're not the same thing. When we ask the saints to be our prayer partners in heaven, we're not getting information from them but giving it to them. That's really the opposite of necromancy which is why there are no biblical passages that forbid it. Does the fact that the bible and the faith forbid necromancy mean that it never works? No, it doesn't