Acts. 4:10-12 Be it known unto you all, and to all the people of Israel, that by the name of Jesus Christ of Nazareth, whom ye crucified, whom God raised from the dead, even by him doth this man stand before you whole. This is the stone which was set at naught of you builders, which is become the head of the corner. Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved.
This is one of the strongest portions of scripture, that speaks of the exclusivity of Christ for salvation. It is becoming not only popular but expected that we believe that everyone can find their own to heaven and be okay. That what is right for one person may not be right for another, that there are many religions that all have the same goal but different terminology. The scripture is very explicit in its denial of this fallacy and those of us that claim to believe that it is indeed the very word of God, have no other recourse but to deny such heresy as well. When one understands the simplicity of the state of man and the justice of God we realize that such exclusivity is necessary.
Here is the situation man is in, everyone born of a woman has sinned. Either we have lied or we have taken something that did not belong to us or we have lusted in our heart and mind, one way or another we have all sinned and that in multiplicity. So then, knowing that the law states that the punishment for sin can be no less than eternal death, how can God grant us entry into heaven. We cannot say "A loving God wouldn't really let a basically good person go to hell". Here is why, what if you came home this evening and found that every member of your family had been brutally murdered, you catch the murderer with blood on his hands running out the back door and drag him to the police. On the day of his trial his defense before the judge is that he is a middle aged man with no record at all with the law. He admits that he did murder your family, but except for that he as never gotten so much as a speeding ticket. Could that judge be loving and merciful and allow that man to walk free because he is basically good? Of course not, to be a good and just judge he must sentence the murderer to what ever punishment the law has dictated. So God would be unjust and unrighteous to ignore his own law and let a guilty man (no matter how "basically good" he was) walk into heaven.
Now let us look at another possible scenario, what if the judge sentenced that murderer, in accordance with the law, to stay in prison until he could pay a twenty-five million dollar settlement to you. Now someone steps up and pays the twenty-five million dollars for that man, he is now free from the sentence of the law because the debt has been payed. So when the book of Acts says that there is no other name given under heaven whereby we must be saved, except for the name of Jesus it is not that ridiculous a statement if you look at it logically. Buddha could not pay that debt for you because he had his own debt to pay, as did Muhammad and Gandhi and even Mary the mother of Jesus was a sinner.
So then we can see that not only is perfectly right that God rejects everyone from heaven on their own merit, but we can equally see that if we will apply the payment of Christ alone for our sins we can be saved from hell in the afterlife and sin in this life.