15 While Jesus was having dinner at Levi’s house, many tax collectors and sinners were eating with him and his disciples, for there were many who followed him. 16 When the teachers of the law who were Pharisees saw him eating with the sinners and tax collectors, they asked his disciples: “Why does he eat with tax collectors and sinners?”
17 On hearing this, Jesus said to them, “It is not the healthy who need a doctor, but the sick. I have not come to call the righteous, but sinners.”
Nobody's perfect. Some are less perfect than others, but all are imperfect.
Some of the neediest folks are "sinners" in the cultural sense, where bad habits and bad choices have put them into tough spots. However, it's those folks that need Jesus the most.
The modern-day analogues of the Pharisees will strive to live holy lives and not to appear to be a part of "the world." That can have them turning down opportunities for ministry that might have them looking a little bit worldly. Shooting some pool at the local watering hole might be a good way to minister to a co-worker, getting some spiritual conversation started in a more comfortable place for an average joe than a Sunday School class, but that would be a double no-no for the legalist. A ..... bar.... and .... pool... (Cue Ya Got Trouble from The Music Man); the next thing you know, the backslider might go dancing.
That might not be a good suggestion for someone with drinking issues, for it might drag them down rather than lift the workmate up, but since the sinners aren't all that likely to wander into a church, we need to go where they are. Easier said than done, since we still need to steer clear of things that are sinful rather than things that are merely associated with sin.