Titus 1:16

What's more is that these people even profess to know God. However, they actually deny him. This doesn't make sense; what kind of person professes to know God but at the same time denies him? The way in which they deny God is by their works. They may with their lips profess a knowledge of God, but their actions prove otherwise. This can be seen everywhere. There are many people who say they know God, but their actions do not align with that of a person who knows God. What Paul says about them is not good; they are detestable, disobedient, and unfit for any good work. I guess this isn't the type of person you want to be, but there are so many like them.