Recurring Thoughts Aren't Automatically God's Voice

Questions about whether having a recurring thought is an indication God is speaking to you, what to say to someone who says they sinned because “God told them to do something” and they didn’t do it, and whether God speaks to us through premonitions.  

• Would you characterize not being able to stop thinking about something as God speaking?
• What would you say to someone who says they sinned because “God told them to do something” and they didn’t do it?
• Does God speak to us through premonitions?