Who were Jesus' friends "the tax collectors?"

How did Jesus treat others, like the tax collector and sinner? 

As Scripture tells us, "God does not show favoritism" (Acts 10:34). Therefore, Jesus treated the tax collector and the sinner in exactly the same way, with grace. 

In biblical times the tax collector was considered by the Jews to be a traitor and very probably a thief. Why? Because the land of Israel was occupied by Rome and the taxes collected went to Rome. There were several levels of authority but the customhouse officers, who were encouraged by their superior to charge compensatory taxes, did most of the real tax collection. These men often charged fraudulent taxes with remedy almost impossible. These tax collectors over charged (Luke 3:13) and brought false charges of smuggling in the hopes of extorting hush money. The tax collectors were called "publicans" and this word means that they were a collector of public revenue. In other words the tax collector worked for the government in charge and that government happened to be Rome. The publicans or tax collectors were considered traitors and apostates. They were also defiled by their contact with Gentiles and because they were working for the "enemy" Rome, they were hated. 

Matthew was such a man. He was a tax collector by trade. "As Jesus went on from there, he saw a man named Matthew sitting at the tax collector's booth. 'Follow me,' he told him, and Matthew got up and followed him" (Matthew 9:9). When Jesus called Matthew, he went and followed and became one of Jesus' apostles. Matthew was a Jew who worked for the Roman government and therefore, he too was hated. 

Therefore, the fact that these tax collectors were hated and considered the worst sinners by most of the population and the Pharisees in particular was that they worked for the occupiers, Rome. "While Jesus was having dinner at Matthew's house, many tax collectors and 'sinners' came and ate with him and his disciples. When the Pharisees saw this, they asked his disciples, 'Why does your teacher eat with tax collectors and "sinners"?' On hearing this, Jesus said, 'It is not the healthy who need a doctor, but the sick. But go and learn what this means: "I desire mercy, not sacrifice." For I have not come to call the righteous, but sinners'" (Matthew 9:10-13). 

Because the Pharisees hated the tax collectors and sinners, they thought that Jesus should too. The fact that Jesus sat and ate with what was considered the dregs of society was an act of grace that the Pharisees could not comprehend. This passage is the answer to how Jesus treated the tax collector and sinner. He called them to repentance and grace. Christ had mercy upon the tax collector and sinner and He always received them because that was why He came. Luke 19:10 says, "For the Son of Man came to seek and to save what was lost." 

http://www.allaboutjesuschrist.org/tax-collector-faq.htm

(Alan: Nor were Israeli shepherds meek people universally loved for their "warm fuzziness." Rather, ancient Jews reviled shepherds whose nomadic lives made it impossible for them to be observant practitioners of God's Law. Shepherds were viewed as outcasts and outlaws, people who not only disobeyed The Law but whose lives obliged them to disobey The Law.)