The Word of God Enables Us to See Our Heart

I heard somebody say recently that the word of God, does not enable us to discern the thoughts and intentions of another person. The Bible says no one can know your own heart. How in the world are you going to know someone else's? You've got a full-time job waiting through this thing to find out what's going on in your own hearts. It's kind of like when Moses could only go so far without doing the circumcision thing on his family. He couldn't go any further until he took shoes off in that place. Sometimes you go as far as you can go and you have to make a decision. And I'll end with this thought out of Romans 10, 17