Religion seems to attract both the needy and those who exploit them.  Of course, that is not the whole story, but arrogant pride (however sweetly camouflaged) can never sit well with the Gospel of the Lord Jesus.  The Pharisees wanted to be admired for their wisdom, righteousness, and holiness.  They wanted to be respected as being close to God.  They were towards the top of the social tree in Jesus' day, maintaining their self-importance by having special seats in the synagogue and receiving reverential greetings in the marketplace.

Christless religion, in its many forms, has a common central feature: if you obey the regulations, you will be accepted.  Some religious philosophies also seem to offer a balance of good versus bad, in which acceptance is achieved by doing more of what is good than bad.  Jesus lived among people who believed that the people who followed the religious rules perfectly were most loved by God.  Many tried to do that.  

Jesus had been pointing out the foolish inconsistency of one generation rejecting the truth and killing the prophets, while their children made heroes out of the dead men but continued to ignore the truth they proclaimed (Luke 11:47-49).  Jesus made the people of His day responsible for the persecution of all God's prophets over the previous 4,000 years.  But that might not seem fair.  Why would His generation be responsible for their deaths? Surely, they could not have been involved, as they were not yet born!

Although there were many people who wanted to hear Jesus and see His miracles, the twelve apprentice-apostles were His first ministry priority.  They would soon have the task of leading the fast-growing church which would eventually spread to every country.  So, they needed to be clear about all the essentials so that they could help many others to believe in Jesus and follow Him.