Ah - I love that quote. I just had it on my FB wall last week. It is:
"Your actions speak so loudly that I cannot hear what you say."
— Ralph Waldo Emerson
Unfortunately, so often we keep trying to read their lips.
That being said, before I kicked XAH to the curb I spent two days gathering rock solid evidence. I KNEW he was using and I KNEW he was cheating. In my heart, I knew. I just felt like I needed the irrefutable evidence so my HEAD would know and so he couldn't convince my heart that it wasn't true. It helped. Every time I kept hearing the "I'm sorry...I love you...I just want another chance" and feeling myself weaken, I thought about what my head now knew and it helped strengthen me.
The tricky part is to make sure that you trust what you KNOW and don't fall for trying to hear those weak words through all the actions.