Differences Between Different Christian Denominations

I sometimes hear things such as 'all who believe in Jesus go to heaven' or 'Jesus loves you'. I think these phrases originate from the US. Possibly that is what American Christians believe.

However, that is not the case with all the Christians.

"American Jesus loves you and Russian one will send you to hell for being a sinner." - Me

I will even list two most contrasting depictions of Jesus I could find:

They do give vastly different impressions.

That is the same with Christian denominations as well.

Some of them lean heavily into one or the other direction, others try to find middle ground.

I would say Eastern Orthodox Christianity as well as Puritans are on the extreme end of ascetism, cruelty and restrictions.

In contrast American denominations, such as Baptists, are probably on the extreme end of all loving and forgiving ones.

How that came this way

The major differences started from Protestant Reformation. 

Both Catholics and Orthodox held and still hold believe that sinners go to hell and only sin free people go to heaven. 

Eastern Orthodox even made the whole faith revolving around earning right to go to heaven after death, by being extremely pious and observant of all religious rules. Fear of eternal damnation in hell reigns supreme over the Orthodox faithful and forces them to comply with Church rules. Alternatively, they become atheist be rejecting the premise of existence of God. This particular denomination holds monks and ascetic monastic way of life in high esteem. Most Church leaders come from monastic background as well.

Catholics were somewhat easier on it and allow people to simply buy a forgiveness for their sins from the Church by giving it money. Just pay and sin as much as you want. That practice made Catholic Church very rich and allowed them to decorate their Churches in very opulent style. This, among other things actually led to Protestant Reformation.

While some protestants went on to embrace poverty and ascetism themselves thus becoming somewhat like Orthodox in process. Most protestant went the opposite way entirely and decided to address the issue of final judgement directly. 

Luther and Calvin went on to address this issue directly. Luther claimed that salvation and damnation is ultimately in God's hands and sin will not necessarily preclude people from being saved and go to heaven. 

Other theologians went even further and said that ultimately solvation and damnation have nothing to do with either sinfulness or faiths. Calvin claimed that each person from their birth is just destined to one or the other from the start and nothing can be done to change that. That latter does not even require any faith at all to be saved and go to heaven.

Later it was simplified by American Baptists into 'all who believe in Jesus go to heaven'.

Later Developments

As Protestant Reformation opened the door for more and more different denominations. Some like Mormons may not be accepted as Christians by other denominations, but they have their origins in Christianity.

Because of that simply knowing that person is Chirstian tells you surprisingly little of what they actually believe in.

Also a Batist Jesus is much better than Russian one.