"One who is faithful in a very little is also faithful in much, and one who is dishonest in a very little is also dishonest in much. If then you have not been faithful in the unrighteous wealth, who will entrust to you the true riches? And if you have not been faithful in that which is another's, 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 be devoted to the one and despise the other. You cannot serve God and money." (Luke 16:10-13).
Trust with riches & relationships are earned. It's amazing how many people misinterpret this passage for Jesus' teaching here isn't rocket science.
If you can't trust a friend to borrow your phone, you wouldn't trust him with your car would you? If you can't trust a person with your heart while dating, you wouldn't marry them would you? An individual's track record with material and emotional things, reveals their character or lack thereof. Those who've proven to you that they are a reputable person of character can be trusted with more and more valuable things. Jesus is clearly stating that it is the same with spiritual things and our relationship with God Himself. Anyone “who proves trustworthy in handling money is a person living under God's rule with the priorities of their life in proper order" (Howell, 243), thus they have revealed who their master is, God. It is not that Jesus “is saying that money is intrinsically evil” only that it serves as a true test since “it is easily abused and used for evil” (Elwell, 828). If anyone fails these tests of trust, it is clear they have perverted their priorities, which “is nothing less than idolatry” (Howell, 243) since they cannot maintain a proper relationship to their true master through exclusive service.