If you would like to tell the reader what all your characters are thinking, you would need to employ a point of view that allows you to gain access to all this information. The best option would be the third person point of view. This allows you to have an "omniscient" narrator, which means a narrator that can see and know everything. In this way, he will be aware of the thoughts of all the characters, and you will be able to include these details in the story.
