Personally, I find a great deal of amusement visualizing all the Christians in heaven, suddenly forced to get along with each other for eternity, regardless of whether they are Catholic, Pentacostal, Westbro Baptist, or Episcopalian with gay ministers. I can't imagine a more unhappy group of people having to share their afterlives.
First, Jesus said:
Many will say to me on that day, 'Lord, Lord, did we not prophesy in your name and in your name drive out demons and in your name perform many miracles?' Then I will tell them plainly, 'I never knew you. Away from me, you evildoers!'
Point being many people are not going to be there, who think they are going to be there. Many people run around pretending to be Christian, and are no more Christian, than I am a Hindu.
Second, you need to understand that in Heaven, we will be given new bodies, and new lives. We will be free completely, from all sin and evil.
When you look at the squabbles between all people, Christians and non-Christians alike, all humans... the problems are all based in our sinful nature. Pride. Lust. Envy. Selfishness. Wrath. Lies.
However in Heaven, all of these things are all eliminated. We won't struggle with them. We won't be tempted by them.
As such, none of that will happen in Heaven. Now Hell on the other hand, the Bible says that those who choose to go to Hell (by rejecting G-d), will end up with an even greater amount of the nature they already have.
Those who are greedy, will be even more greedy in Hell. Those who are prideful, will be even more prideful in Hell. Those who are angry and full of wrath, will be even more so in Hell. How does that work? I have no idea, but thankfully I'm not going to find out.