“If our hearts are entirely given to God, it is clear that we cannot serve two masters; it is simply impossible–at any rate all the time we are following Christ. It would of course be tempting to show how far we had advanced in the Christian life by endeavouring to serve two masters and giving each his due, both God and Mammon. Why should we not be happy children of the world just because we are the children of God? After all, do we not rejoice in his good gifts, and do we not receive our treasures as a blessing from him? No, God and the world, God and its goods are incompatible, because the world and its goods make a bid for our hearts, and only when they have one them do they become what they really are. That is how they thrive, and that is why they are incompatible with allegiance to God. Our hearts have room for only one all-embracing devotion, and we can only cleave to one Lord. Every competitor to that devotion must be hated. As Jesus says, there is no alternative–either we love God or we hate him. We are confronted by an “either-or”; either we love God, or we love earthly goods.”
Dietrich Bonhoeffer in The Cost of Discipleship (New York: MacMillan, 1963) 195-196.
No servant can serve two masters. Either he will hate the one and love the other, or else he will be devoted to the one and despise the other. You cannot serve both God and Money. Luke 16:13