No one can serve two masters, for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and money.
We try to serve two (or more) masters all the time. We think we can do it by dividing up our lives. Serve God in this section. Serve money in this section - although we would never say it like that, it would be something about needing to work longer hours to pay the mortgage, or talking about "needing" that new phone. The problem is that the "masters" will eventually come into conflict and whichever one you're truly serving will win. So we claim to be serving God but our giving to church is the first thing to get cut if our financial situation changes. We see somebody in need but are not willing to do anything to help that would impact our standard of living. Money wants your entire devotion, it wants your life. Jesus wants your entire devotion, He wants your life. Money will enslave you - you think it's serving you but you're the one making sacrifices for it. But to have Jesus as your Master is to find real life.