Jesus did not just randomly call Levi out of the crowd. Levi was a tax collector, and to reach tax collectors, you need a tax collector to be the ambassador.
There are at least three ways I see Jesus working here.
Tax collectors were despised by the people. They worked for the occupying government of Rome. A Jewish tax collector was considered a traitor to his own people. There was a certain percentage that the Roman government required to be collected, anything above that percentage the tax collector could keep. So, Levi was actually making money by increasing the percentage people were paying in taxes. No wonder the people hated these officials.
No one but a despised ex-tax collector would even care to reach despised tax collectors.
On several occasions the religious leaders of the day accused Jesus of eating with tax collectors and sinners. It wasn’t so much that they hated the idea of taxes for the people, but they hated that those taxes went to Rome and not to them. Like any politician, they pretended to be for the people and not associate with this hated group. But Jesus broke that barrier. He wanted to reach even this despised group of people. He did so by having a tax collector in his group. The next thing we see is Jesus eating in Levi’s home and calling his guests to repentance. The second thing we see is that tax collectors were wealthy people who lived in a different class, they wouldn’t even think about having Jesus at their table.
But because they knew Levi, they were willing to hear what Jesus had to say, therefore they received Him.
Religious people only see the sin, Jesus sees the person. True, we are not to associate with those who are not walking in the truth, but that applies to those who are subversive to it. If your best friends are those who are constantly trying to get you away from Christ, then you shouldn’t spend much time with them. However, if they are open to hearing what you have to say, then by all means you should reach out to those people.
Why does God save pot-heads, junkies, partiers and the like as part of his team? To reach pot-heads, junkies and partiers and the like. God may have saved you out of the muck and mire of a sinful lifestyle. Great. He just might have saved you that your heart of compassion for your community, whatever that was, might be soft toward them and have a great opportunity to introduce them to Jesus, the Savior who changed you.
Your “BC” experiences may be the gateway through which Christ comes and dines with your friends.