Luke 16:12-13

And if you have not been faithful in the use of that [earthly wealth] which belongs to another [whether God or man, and of which you are a trustee], who will give you that which is your own? No servant can serve two masters; for either he will hate the one and love the other, or he will stand devotedly by the one and despise the other. You cannot serve both God and mammon [that is, your earthly possessions or anything else you trust in and rely on instead of God].”