“If ye have not been faithful in that which is another man’s, who shall give you that which is your own?” (Luke 16:12). Jesus is saying, “You say you want a revelation, something to enable you to do greater things. Yet, how can you be entrusted with that kind of faith, if you’re not reliable with the things others have given you?”
Jesus’ words must have left his disciples scratching their heads. Their Master knew they didn’t own anything, much less something that another person had given them. They’d forsaken all to be his disciples. And they had followed him to the best of their ability. His words here simply didn’t seem to apply to them.
What does Jesus mean when he says, “that which is another man’s” (16:12)? He’s speaking of our bodies and souls, which he purchased with his own blood. “Ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God’s” (1 Corinthians 6:20).
Jesus is telling us, “Your body doesn’t belong to you anymore, And if you don’t take care of that body—if you won’t allow me to look inside you, deal with your sin, and sanctify you—how can you expect me to entrust you with something greater?”
The disciples had requested an increase of faith and Jesus had a ready answer for them: “If ye had faith as a grain of mustard seed, ye might say unto this sycamine tree, Be thou plucked up by the root, and be thou planted in the sea; and it would obey you” (Luke 17:6).
What could Jesus be suggesting with this image? I believe this statement is about plucking up the roots in our hearts. Jesus is speaking of roots of evil, the hidden things we must deal with as his followers. He’s saying, “Before you can believe God to move mountains, you need to remove roots. And you don’t need some great, apostolic faith to do that. All you need is the very least amount of faith. I’m asking you to do something very basic: to pluck up the roots of sin. I want you to examine your heart and remove everything that’s unlike me.”