Minuteman said

“Those who had been Momin and Those who had been Jews and Christians and Sabians, whoever believed in Allah and the last day and did good deeds, their reward will be with their Lord and they will have no fear and will not be grieved…”

But the verse says, “Those who are believers and those who are Jews and Christians…. Whoever believes in Allah and the last day and does good deeds…..”

 Remember that Momineen or Muslims are included in all this. And the Jews and the Christians, whoever believes in Allah. That means only the atheists are excluded. That is the benefit of mercy of the attribute Al-Raheem of Allah.

Brother, to understand a verse, we need to go thru its commentary, which gives us a good explanation as is supported by hadith. We are n't learnt person or know arabic, that we understand Quran directly. Both of us know our levels of knowledge. And we are very very far from interpreting these verses of Quran. We need to be very careful while doing so.

Coming to the understanding of the verse, Its said that jews, christians and believers --- which means those Jews who believed in Allah swt and followed Musa AS, those christians who believed in Allah and Isa AS, and those momin who believed in Allah and Muhammad [sallal lahu alaihi wasallam} . You refer to the tafseers and then do comment. Its not just muslims who are entitled to heavens but those jews and christians too who were believers then. A person needs to believe in Allah and Prophet {saws}  as its said in the Quran.

"The religion before Allah is Islam." [Surah Aal-`Imran(3), 19]

"Whoever desires a religion other than Islam, it will never be accepted from him, and in the hereafter he will be among the losers" [Surah Aal-`Imran(3), 85]

The Prophet (peace and blessings be upon him and his Household) has said that even if Moses were alive on the earth today, he (Moses) would have no option but to follow him (Muhammad)

[Reported by Abu Dawud}

 Al-Raheem of Allah.

Remember this attribute of Allah swt is for whole humanity irrespective of any religion. But on the day of judgement, we need to fulfill the qualification for entering Jannah. It does n't mean we muslims be care free that we are entitled to Jannah. We enter there only after facing our punishments.

"And the (Hell)Fire will be placed in full view of the erring. And it will be said to them: "Where are those (the false gods whom you used to set up as rivals with Allah) that you used to worship?" Quran 26:91-92

"If you join others in worship with Allah, (then) surely, (all) your deeds will be in vain." Quran 39:65

"And whosoever of you turns back from his religion and dies as a disbeliever, then his deeds will be lost in this life and in the Hereafter, and they will be the dwellers of the Fire. They will abide therein forever." Quran 2:217

is KUFFAR and SHIRK same

You know Poga, when we do something intending to show others, instead of Allah swt, then it is also Shirk. Any act of ours if intended to show it to the people around us, like salah, or fastings or any other deed, instead of for the sake of Allah, then it is also a type of  shirk we commit. Its a very deep topic to be discussed.

By the way, minuteman, as there are no other topics going on, i was reading this again and found that you did not answer my question

From where did you get this definition  and understanding that enemity is a must  for Kufr ? Did you read it anywhere ?