We live in a world that says all religions are the same. It claims that we all worship the same God regardless of which religion we belong to. And it says that we are all going to heaven when we die. The official ideology for this kind of belief (the idea that all thoughts are equally valid and equally true) is called relativism. 
But does this view hold any merit? Is it even possible? 
In order to decide, we will first look at the basic tenets of three major world religions. This will include looking at how each of the three religions answers the questions of 
1) Where did we come from? 
2) What is our biggest problem? 
3) What is the solution to that problem? 
4) And what happens when we die? 
After these questions are answered, we will be able to see if these three religions are compatible. Finally, we will draw a conclusion about the validity of relativism and whether all religions are the same.
First up, Christianity.
Basic Beliefs of Christianity
Where did we come from? There is one triune God who is sovereign and eternal. He created the world and everything in it by speaking it into existence.
What is our biggest problem? We have all chosen to rebel against God, and we have all disobeyed His perfect commands. God is perfect and holy, and we cannot have a relationship with Him because we are imperfect and sinful. Our disobedience merits the wrath of God and eternal separation from Him in hell.
What is the solution to that problem? God’s Son, Jesus, took on human flesh and became a divine Man. Jesus lived the perfect life that we could not live. He willingly took our sin upon Himself and received the wrath of God on our behalf by dying on the cross. Those who believe in Him and turn away from their disobedience receive His righteousness and enter into relationship with God.
What happens when we die? Those who believe in Jesus go to heaven to be with God forever, and those who do not believe in Jesus receive the eternal wrath of God in hell.
Next up, Hinduism.
Basic Beliefs of Hinduism
Where did we come from? Brahma is the creator god, Shiva is the destroyer god, and they exist alongside 330 million other gods. When the world sinks to its moral low, Shiva destroys it. Then Brahma recreates it. It has always been this way.
What is our biggest problem? Just as the world exists in a cycle of death and creation, so do individual people. They need to get free from this reincarnation cycle, but they are ignorant of the inner knowledge of truth that is needed to do so.
What is the solution to that problem? By looking inward at oneself, people discover that their purest existence is with Brahman (the ultimate universal principle or highest reality of all). By following the caste system and living with contentment, folks rid themselves of all misconceptions and worldly desires. This opens them up to becoming enlightened so that they may discover their transcendental state and be liberated from their material existence.
What happens when we die? Those who have attained enlightenment are absorbed into Brahman and escape the cycle of material rebirth, and those who haven’t attained enlightenment are reborn into a new material body in accordance with their works from their previous life.
Lastly, Evolutionary Darwinism.
Basic Beliefs of Evolutionary Darwinism
Where did we come from? A big explosion eons ago eventually led to the formation of a living, single-celled organism. Over time, that cell multiplied and life evolved into more and more advanced organisms, finally resulting in the existence of life as we know it.
What is our biggest problem? We get bogged down in religion and judgmentalism so much that we aren’t able to enjoy life.
What is the solution to that problem? We should be more tolerant of everyone’s beliefs and accept the fact that we are merely material creatures with no greater purpose in life. We should live life to the fullest now.
What happens when we die? We cease to exist.
Are Christianity, Hinduism, and Evolutionary Darwinism Compatible?
In terms of where we came from, Christianity posits that we were intentionally created by the one and only God of the universe. Hinduism claims that the creator god and the destroyer god have been cyclically creating and destroying forever. And Evolutionary Darwinism theorizes that we came about by chance with no intelligent guidance as the result of a big explosion. One God cannot simultaneously be multiple gods. And our existence cannot have come from both intelligent guidance and non-intelligent randomness.
In terms of our greatest problem, Christianity believes it has to do with our disobedience to God. Hinduism thinks it is about a lack of knowledge that impedes true self-discovery. And Evolutionary Darwinism claims that our religious beliefs themselves are the problem. The problem cannot be both religious and non-religious in nature. And it can’t be about both pursuing pleasure and ridding oneself of it.
In terms of the solution to the problem, Christianity requires faith in Jesus, Hinduism requires looking inside of oneself, and Evolutionary Darwinism claims that tolerance is key. But all of these solutions are mutually exclusive in that they cannot exist alongside one of the other solutions. The solution can’t be both within oneself and outside of oneself. And even religious tolerance is contradictory because it says that all religions are true except for the ones that don’t affirm all religions as equally valid.
Finally, in terms of final destination, Christianity says we end up either in heaven or hell, Hinduism believes in either reincarnation or spiritual absorption into Brahman, and Evolutionary Darwinism believes in the complete extinction of both body and soul. The body and soul either continue after death or they don’t. It can’t be that the body and soul both continue to exist and cease to exist.
Claiming that all three of these religions are true is simply not logically possible. By definition, if they are different, then they cannot be the same. Even the most basic of their tenants are undeniably contradictive. And this is only three of the more than 4,000 religions around the world! 
All religions can’t be the same because they don’t even claim to be the same
We indeed came from somewhere, and we indeed are going somewhere when we die. But if the different world religions don’t claim to have the same origin and also explicitly claim to lead to contradictory places, how can they possibly all be true? The answer is that they don’t and they can’t. There is only room for one true religion, and all of the rest of them are lies.