It’s not what goes into your mouth that defiles you; you are defiled by the words that come out of your mouth.”
Your words are powerful. As scripture says the power of life and death lies in the tongue. Our words are an exact reflection of us. It is a reflection of the state of our heart. This is one of the reasons we often hear this saying “Do not speak when you are angry”.
This is because often times in our anger we pour out all our frustrations and all our filthy thoughts, which are the reality of our hearts.
You must understand that the fullness of your heart is what comes forth. Therefore you are indeed defiled by what comes out and not what goes in. If your words are filled with pain, and bitterness, and all manner of negativity ask yourself what the state of your heart is. Take stock of all the words coming out of you and ask yourself if it looks like Christ. If your words do not resemble Christ then you need to go back into your secret place and seek to look like Him. You must sound like Him as well as look like Him. Again words are powerful. Therefore dwell in Him, indulge in His word, so that the very things that come out of you are those that are of Him.