'For we all stumble in many things. If anyone does not stumble in word, he is a perfect man.'
To be perfect just say all the right stuff and mean all the stuff you say.
'But no man can tame the tongue. It is an unruly evil, full of deadly poison. With it we bless our God and Father, and with it we curse men, who have been made in the similitude of God. Out of the same mouth proceed blessing and cursing. My brethren, these things ought not to be so. Does a spring send forth fresh water and bitter from the same opening?
The tounge is an indicator of the heart. What you desire is exposed in your words. We speak about whatever makes us happy. If you love God you'll speak about Him.
Get a new heart from Jesus if you don't have one already.