How to preach this?

So how do we preach this consept, or let me rephrase myself; how do you tell other people they need to regret? 

Doesn't that make you and me into a judgemental person and at the same time we risk being a victim of the "Accuser?"
This is complicated, but at the same time very easy and I have (once again) walked this road by myself and experianced the alternatives; 

 
Even if this complicates things (preaching becoming judgemental) it actually puts a "quality stamp" on the consept. I'll try to explain what I mean by that; since I (and hopefully you) don't wanna be a victim of the accuser and at the same time you wanna make this work for those you would like to help out, it's no point in "pushing" other people to admit they need to regret anything before they really understand they need to do so by themselves.
Why?
Because they're not interested before they (hopefully one day) ask you about your own experiance. This means we have to "live it!"

You have to "live it" 

I beleive we need to contextualize the gospel and (if asked) tell people Jesus may be a source of joy and "at service" for them. Jesus have something to offer us all, he will give you peace at heart and a good life in this lifetime and a heavenly experiance in the next lifetime.  

And the best way to show other people this being a fact is by live in peace at heart in this lifetime, if they get curious about "how and why you always are happy or at least seem to be", they migth ask you about how and why. Only then it's time to tell them the truth.

I know there are people whom are challenging to be around from time to time, they seem to have the ability to drain all the energi out of you or you just find it hard to cope with their attitude and way of handling themselves. What to do in those cases?
In my opinion you'll have the ability to choose your own company, but lets say you don't (migth be the case in certain situations), please don't tell them your opinion unsolicited. Instead of telling them your opinion about their "attitude"; Think it!
Don't fall into the trap, because that's what it is; A trap for you to be judgemental and therefore a victim of retaliation.

In other cases you'll meet resistance againt your way of living, and then we're talking about humans whom challenge your relationship with God. They will try to make you "go their way" instead of keeping your contact with God. I say in those cases; don't walk away, run!