In Matthew 6:19-24 Christ gives three sayings that all describe what it looks like to be truly devoted to God. It means seeking treasure in heaven, having a good eye that looks to the glory of God, and that serves God rather than Mammon. Ultimately, everyone must choose whom they are going to serve: God or something else. Christ warns against the kind of self-deception that believes you can do both. Be warned! You cannot serve two masters.