The unstated assumption behind this illustration is that the two masters have different instructions and different interests, and desire to be served in different ways, and therefore no servant can serve both of them at the same time. As soon as he thinks about what one of them would like him to do, he realises that this is going to upset the other; but if he switches to the interests of the second, he will displease the first.
The divided man attempts to gain the world and to have salvation at the same time. He can never truly bring himself to resign from his service to the world, for he has not seen the reality of the reward that God gives. He thinks that he can have both heaven and earth at once and therefore gathers treasure on earth at the same time.
Even a believer can be in in danger of this, can be that unfortunate slave. But can a believer hate God and love the world? Yes, it can happen in this way: We preach the standards of the Bible. You open the Bible yourself and you see them. My church teaches that I am not supposed to go into night clubs or discos. In these days that is so offensive to the Lord with the sexual connotation of modern dance – it is hard to think of anything more decadent than that. They will not let me go to just any movie. They do not like me dressing however I like, however provocative and suggestive it is. They want me to serve the Lord and volunteer. I do not like that. That is the way a believer ends up hating the Lord. He goes and finds a worldly church that claims to be Bible believing, but allows you to do what you like. That is like ancient idolatry. That church has dropped all the spiritual standards and the standard of service and godliness. You cannot balance your commitment to the Lord and your love for trivia and the covetous type of things in this world. So if the believer has means and has wealth, and a high position, he need not necessarily give those things up, but he must not be seduced by them. He must steward his means, he must practise self-denial, and not immerse himself in unnecessary luxuries. If it begins to seduce you, you had better give it up because it will ruin your spiritual life.