I want to use device contacts in Google messages

[Android Central Question]

I have new Samsung phone(Android Version 7.0). "Messages" contacts is from existing list from our Gmail account, which my wife also uses. I want to use my own contacts. I have moved this in and it appears in "contacts" app as "device" contacts, though Gmail contact also appear as another alternative. How do I get my phone to use these "device" contacts instead of the Gmail contacts specifically in Messages app. Note I do not want to risk deleting Gmail contacts because my wife uses them on her phone.

Thanks