Jesus really didn’t get on with the religious leaders of His time.
In Matthew 9, Jesus pushes some boundaries when He invites a tax collector called Matthew (yep, the author) to be in His inner circle—one of the twelve disciples.
Tax collectors were bad news. At a time when Israel was under Roman control, the tax collectors worked for the Romans: they were traitors. Not only that, but they were notorious for demanding more tax than legally required, and lining their own pockets with the excess: they were cheats.
To make matters worse, Jesus goes to this Matthew’s house for a meal, and sits around eating and talking with Matthew and all his tax collector friends.
When some of the religious leaders—the Pharisees—see this, they decide to confront Jesus’ disciples.
The Pharisees took a great deal of pride in their lifestyle, observing all the sacrifices and religious requirements as laid out in the Hebrew scriptures (the Old Testament), which they knew back to front: their knowledge of scripture was unparallelled. In short, they were the epitome of holier-than-thou.
“Why does your Teacher eat with tax collectors and sinners?” the Pharisees interrogate, with supercilious sneers.
But Jesus overhears the challenge, and intervenes.
“Those who are well don’t need a doctor,” Jesus explains axiomatically, “but the sick do. Go and learn what this means: ‘I desire mercy and not sacrifice.’ For I didn’t come to call the righteous, but sinners.”
The quotation Jesus uses to attack the Pharisees’ pretension (in which God tells the Israelites what really matters to Him) is from the Book of Hosea—from the very scriptures the Pharisees pride themselves on understanding.