He sent us to this world, and we all have to try our best to strive to get to paradise. This means, sacrificing your wealth to support the needy, and to worship God alone without any partners. This means fighting in jihad (to end all oppression) and to enjoin people to the truth (to islamic monotheism.)
This is what most Christians believe. There are definitional differences. For example, I assume you would consider Jesus a partner. In Christian belief he is not a partner but at the same time He and God are one (through the Trinity). Ending oppression, sacrificing wealth are all also Christian tenets. Jihad, as it is used by many Muslims, is not particularly Christian (killing of innocents) but certainly many Christians have used their faith to justify sins as well. There is also a call to to the truth and to be more evangelical, but obviously not to Islamic monotheism.
You are incorrect that all Christians agree that simple belief gets one to Paradise. In fact, that is relatively uncommon. Many churches believe that they are the one true religion and that only their members achieve that goal. My own tradition does believe in a loving and forgiving God and that Paradise after death is reserved for those who truly believe and repent. Certainly that can lead to many to think that nothing they do on earth matters as long as they make a repentence, and they may be right--it is, after all, up to God only. It does not release us from our duty, however. As humans, we will make mistakes. We should strive to be perfect but none of us are.