They claim to know God, but by their actions they deny him. They are detestable, disobedient and unfit for doing anything good. - Titus 1:16
Our actions are an indication of whether or not we know God. We can claim to know God with our words and with our thoughts, but still deny Him by our actions. According to the apostle Paul, if we think our actions don’t matter, then our thinking and our very consciences are thoroughly messed up.
How we live, what we do, how we treat others, and what we say is either an act of praise to God or an act of denial. So, are you praising God or are you denying God?