Jesus in the gospel tells us that we cannot serve both God and the world. It is like what the scripture says in the book of Revelations 3:16-18 namely, I wish that you were either hot or cold. Since you are lukewarm, I will spit you out of my mouth. What this amounts to is that it is not enough for us to be Christians on Sunday and pagans on weekdays. And yet many of us do try to straddle goodness and evil.
Let me tell one of old Korea stories about a man who would not try to be both bad and good. I had been on a bus ride across the Korean countryside. Coming back on a Saturday afternoon, the bus broke down twenty miles from my parish. This man came up to me suggesting that we split the cost of a taxi.
Sitting with him in the back of the cab, I asked him how he knew me. He said he had seen me passing by his shop for the last ten years. Then he explained people like him made their living by cheating people. They recognized they would be hypocrites by coming to church. I asked him how he could talk that way when he believed in God, and he told me that for every five years of cheating people he shaved his head and he spent one year as a monk doing penance.
What God wants is for us to be with him seven days of week.