In the parable of the prodigal son (Luke 15:11-32), there are two sons: the younger son, who runs away from home to an alien country, and the older son, who stays home to do his duty. The younger son dissipates himself with alcohol and sex; the older son alienates himself by working hard and dutifully fulfilling all his obligations. Both are lost. Their father grieves over both, because with neither of them does he experience the intimacy he desires.
Both lust and cold obedience can prevent us from being true children of God. Whether we are like the younger son or the older son, we have to come home to the place where we can rest in the embrace of God's unconditional love.