6 Do not give dogs what is sacred and do not throw pearls before swine, in case they trample them under foot and turn to gore you.
Bible verses about "guarding your heart" | Moffatt
1 Since then you have been raised with Christ, aim at what is above, where Christ is, seated at the right hand of God;
5 So put to death those members that are on earth: sexual vice, impurity, appetite, evil desire, and lust (which is idolatry),
45 The good man produces good from the good stored in his heart, and the evil man evil from his evil: for a man's mouth utters what his heart is full of.
2 Instead of being moulded to this world, have your mind renewed, and so be transformed in nature, able to make out what the will of God is, namely, what is good and acceptable to him and perfect.