It's dangerous to think that you know someone better than they know themselves.
First, it's dangerous if you're wrong. You may see certain aspects of a person clearly, but it's unlikely that you have all the data. So you can possess a distorted view of someone which is very compelling to you. Then, you reflect that view back to them, directly or indirectly.
But also, it's dangerous if you're right. You have a lot of power if you understand someone better than they understand themselves. You'll know better how to defeat them in arguments. You'll approach them with a settled confidence about who they are which they can't contradict -- after all, you're the one with a better command of the facts of who they are. You set yourself up as the trustworthy, wise one, and the wise are those whose decision-making has legitimacy, and thus social power.
When in possession of this power, you can put the other person in a dependent state, setting their horizons within the bounds of your vision. This can prevent them from being the person that God wants them to be.
Which is better, to know someone accurately, or to share the same reality as them? People who share the same reality can be friends. So you make the choice (or life makes it for you): to see things your way (to see the facts) or to share a journey with someone else.
If you know someone better than they do, you don't need to listen to them anymore. Speech is how we create reality, how we express ourselves.