In Jesus' parable of the tenant farmers (Luke 20:9-19), we have reached the part of the story where a number of the owner's servants were violently denied access to the vineyard and its produce.  Finally, the owner sent his son.  However, the tenants carried their rebellion to the limit and killed the heir, assuming that they would have the ownership of the vineyard.

Jesus was speaking prophetically, just a few days before His crucifixion, and exposing the motives of Israel's religious leaders.  They were selfishly determined to retain their own religious position and power. In order to do that, they were resolute in their decision to kill Jesus (Luke 19:47).
 
This parable intentionally pivots on the 'son' - who is Jesus Christ, the Son of God.  The implication must have been unmistakable.  Jesus described Himself as being greatly loved by the Father but hated by the priests and religious leaders who had no respect for Him.  They did not understand that He carried the full authority of Father God and that one day they would be accountable to Him: but He did not fit into their thinking. To eliminate the Son, they believed, would eliminate every threat to their personal ambitions. But they had no idea of the disaster that would befall them and their religious ambitions (Matthew 24:45-51).
 
Alas, it is still the way for many religious people today.  Some focus on how they can achieve entry to God's kingdom through rituals, rule-keeping or purity.  Others use their religion to achieve their own ambition.  Either way, if they reject Jesus Christ as their Lord they do two terrible things to themselves: they cut themselves off from His salvation, plunging themselves into the horrors of a godless eternity (Matthew 25:30); and they ignite the jealous anger of Father God (John 3:18).  The Father's love for His Son is so intense that rejecting Him, automatically rejects them from God's presence.  That is true irrespective of the sincerity of what people believe or the zealous piety with which they practise their religion.  In short, reject Jesus and be rejected by Father God (Matthew 10:33).  Conversely, receive Jesus and be welcomed into God's presence!  This is the essential message of the gospel (www.crosscheck.org.uk) which every believer needs to be able to explain and share; because so many are religiously deluding themselves ... and they need to know the truth.