I've been downloading this lately, though not super impressed with it, what in the hell was up with this segment last night? Why does Bill Maher hate Colbert so much? There were some awkward and depressing exchanges to watch in this interview, and I understood none of it.

Religion or no religion, Bill Maher has been and likely always will be a dick with poor tact and lacking any kind of gracefulness.

Gotta say, I was skeptical of Colbert leaving his persona but he is even funnier as himself.

OK, consider if Colbert was trying to get Maher to come back to the KKK, or Daesh.
Asking a staunch atheist to 'come back to the church' is the same level of disrespect and the organization holds near the same amount of disgust in many people's minds.
Considering that, I thought Bill was being quite nice and friendly. I mean, he didn't say "Fuck you, Colbert, why would you try to re-indoctrinate me in your stupid bigot club that you don't even follow properly yourself." which would have been an appropriate response.

I think that would have been an over the top response for what was clearly meant as a bit of a joke.

OTOH, I think Colbert got a little overly defensive toward the end.

The problem is that this kind of show isn't a place for a serious discussion and people tend to be pretty humourless with regard to religion.

Theists don't appreciate the flaws in their beliefs being pointed out and atheists don't like people attempting to indoctrinate them.

I'm definitely on the other side of the, uh... pew?, but to me Colbert would be the one I'd accuse of the part I bolded in your comment -- at least in this specific scenario.

I'd agree that outside of this meeting of the two, if you consider the two of them separately as the individual helms of their individual shows, Colbert is certainly more tactful and graceful when broaching touchy subjects like this than Maher is. But on the other hand, I think that whatever Maher may lack in tact and grace, he makes up for in "calls it as he sees it" honesty and usually pretty solid logic.

I like both of them.

My opinion is hardly based off of simply just this interaction. It's years worth observation of how he interacts with guests on his show and seeing him live on stage.
He is not appear to be a very pleasant person to interact with. Don't let the subject matter of this clip get in the way of a pretty nasty personality. Many others would have answered Colbert with way more grace and tactfulness is all I'm trying to say.

Full interview *related http://videosift.com/video/Colbert-Late-Night-Bill-Maher-Full-Interview

Colbert Late Show Bill Maher Full Interview has been added as a related post - related requested by eric3579.

Colbert is trying to convert Bill Maher to his religion, but religion cannot save you. A religion is mans attempt to reach God by his own merits, but there is nothing we can do to reach God on our own. The reason Jesus Christ died on the cross is because man is utterly unable to merit his own salvation. A lifetime of good works, added up together, cannot wipe out a single sin.

Our sins are wiped out only by the sacrifice that Christ made on the cross, when He paid for the sin of the world. His payment for our sins is accounted to us when we put our trust and faith in Him as Lord and Savior. We will all pay for our sins either on our own merit, or on the merit of Jesus Christ, who was accepted as a sacrifice for sins by God because He had never sinned and met Gods righteous requirement of moral perfection.

Colbert isn't alone; we are all bad at this. We cannot live up to Gods requirements, but God sent His Son Jesus Christ to do what we can never do and pay the price we cannot pay so we can be reconciled to God and obtain eternal life.

You're not absolved of any sins unless you repent and place your trust in the Savior. There are plenty of people who believe but die in their sins; the scripture says that the demons believe, but it isn't doing them any good. You have to be born again, and that only happens when you turn from your sin and turn towards Jesus Christ as Lord and Savior. The sin that keeps us from eternal life is rejecting Jesus, the Messiah. That's either rejecting Him in belief or unbelief.