What does Mark 12:1 mean?
In Matthew's Gospel, this is the second of three stories comparing attempts to use God for worldly gain against sincerely following God. In the parable of the two sons, Jesus conveys that tax collectors and prostitutes, despite their initial rebellion, choose to follow God more closely than the religious leaders (Matthew 21:28–32). Here, the "tenants," or religious and civil leaders, assume a higher station than they warrant, and God promises to reward their presumption with destruction (Mark 12:9). In the parable of the wedding feast, the nobles who reject the invitation of the king will be replaced by whatever commoners are willing to come. In all three cases, the religious leaders overestimate their importance to God and, if they do not repent and follow Him, will find themselves deposed.Jesus' use of this parable involves an unexpected twist. Scholars relate the parable to Isaiah 5:1–7, as this verse has many of the same details as Isaiah 5:2. In Isaiah, God builds a vineyard, representing Israel, but only wild grapes grow, representing rebellious Israelites. In response, God promises to destroy the vineyard: their exile into Babylon (2 Kings 24:10). It's possible, at first, that the religious leaders see themselves as the landowner in the parable: the rightful "owner" of the Jewish nation, and the tenants as the Roman occupiers. It isn't until Jesus mentions the "servants" (Mark 12:2–5), a term used in the Old Testament for prophets (Jeremiah 7:25–26), that the leaders understand what Jesus is saying.
Reading these words two thousand years after the resurrection, the roles in this allegory are clearer. The landowner is God. The tower is God's protection over Israel, Judaism, and the temple. The tenants are the religious and civil leaders (Matthew 23:31). The trip the landowner takes could be the four hundred years of silence between Malachi and John the Baptist, but it can also mean the entire history from Joshua's conquest of Canaan until this point.
Assigning a specific identity to the vineyard is harder. Not every single nuance of a parable is meant to have a specific application in the real world. If the vineyard is meant to have a specific meaning, it appears to be the Jewish people, but considering they will be dispersed with the "tenants" during the destruction of Jerusalem in AD 70, the meaning is probably broader. The valuable farmland is God's favor, the way of salvation, and the knowledge of how to worship Him. These responsibilities will pass on to the church, which is the "others" of Mark 12:9. At this time, however, the listeners would have no way of knowing this.