Luke 16:10-12

Trustworthiness does not depend on the amount for which one is responsible but on character (cf. 1 Timothy 3:5). Faithfulness in the use of money now demonstrates a trustworthy character that God will reward with responsibility for greater riches in the kingdom. Unfaithfulness does not just demonstrate untrustworthiness but unrighteousness. By using the word "mammon" Jesus probably intended the disciples to include all the worldly things in which people trust, not just money. These would include one’s time and talents as well as his or her treasure. If disciples squander what God has entrusted to their care on the earth, who will give them their own things to manage in heaven, such as authority over others in the kingdom (cf. 1 Corinthians 9:17)? The rhetorical question answers itself. God will not.