Here is Christ’s positive lesson which we are to draw from this parable. Like the unjust steward, we are to make friends by using the mammon of unrighteousness.
It is impossible to have a right attitude to earthly riches unless we have faith in God. Only when we see that this life is transient, and that we must leave all behind when we die and take nothing with us, do we start to view earthly riches correctly. As those who love the Lord Jesus, we desire to be with him, and all our hope is fixed on the life to come. Earthly riches do after all have a heavenly use, but not because they can be transferred into a heavenly bank account. No, they must remain here. And yet we may benefit other believers with them while we are in this world, and although our money will not go to heaven, those believers will go there, and they will remember our kindness to them while we were on earth. They have no power to bring us to heaven themselves, but they will welcome us to heaven when we arrive there by grace. They will express gratitude to us for what we did to them when they were in the world with us. All these things are very revealing about the nature of relationships in heaven.
This verse has been described as divine sarcasm, and treated as the opposite of what we should do. The thinking behind that view of the verse is that Christ would never tell human beings to try to secure their place in heaven by making friends. No friend in heaven can bring us to heaven, or ensure that we are provided for there. Only Christ can redeem us from sin, and pay with his blood to have our sins forgiven. The way of salvation is only ever to repent of sin, and trust in Christ’s atoning death on Calvary. But the verse is not telling us how to obtain salvation. The words, ‘Make to yourselves friends of the mammon of unrighteousness; that, when ye fail, they may receive you into everlasting habitations’ are a truncated expression, which is teaching us about a use of earthly riches that is consistent with the life of.