No where in my post did I say we should tell people they suck. Jesus didn't just hang out with sinners, he preached to them. He told them the truth about how to enter heaven, how to live their lives. The apostles did the same thing when they went out. They told the unsaved that there was a way to heaven and how to get there.
My father has the same idea as you about just loving them and hanging out with them. He has a ton of friends he has had for years and never once shared the gospel with them and they are all still atheists, agnostics (unsaved). This type of Christianity isn't love, it is tolerance. Love is telling them the truth.
Ephesians 4:15 (NASB)
[SUP]15 [/SUP] but speaking the truth in love, we are to grow up in all aspects into Him who is the head, even Christ,