You've heard it said that Christianity is not a religion but a relationship. But is that the only that makes it different from other religions? No, it's not. There are so many things that make Christianity different, but for the sake of our sanity, I've listed only five.
1. Our God loves us unconditionally
I think this is the biggest marker of them all. There is nothing else in the world that will love you unconditionally. No other religion says that their god(s) will love you no matter what you've done or what you will do. Our God does that. In fact, He loves us so much that He gave His ONLY Son to die a horrific death on a cross for us. No other god has done that. We disobey Him time and time again, yet He is faithful to our call every time. He meets us with open arms and removes all of the shame and guilt from our lives. Most religions demand something from us. God's love causes us to want to love Him and live for Him. We see the depth of His affection, and we respond with giving Him out lives.
2. We can't earn anything
No matter what we do, we will never be worthy of any of God's blessings. Even so, He lavishes His gifts on us. We could work a thousand lifetimes and never earn His grace. But that's really the whole point of His grace -- it's unmerited. In other religions, you work, you pray, and hope that you can earn favor from the god(s). In Christianity, when you accept Christ as your savior and repent of your sins, the righteousness of Christ is given to you. This means that you walk in the favor of God. You don't have to work to earn it. You have it.
3. He speaks to us
To some people, this seems crazy, but it's real. It may not be a auditory voice ringing in your ear, but you can recognize it. He speaks to you through His word and in your everyday activities. You just have to open up your heart and take time to listen. The more you read His word, the more likely you will recognize His voice. What He says to you will always line up with what His word says.
4. Our God is personal
He knows each and every one of us personally and intimately. He knows the number of hairs on our head, He knows what our life is like, He knows our dreams and goals. He isn't distant or ignorant. He is not too busy to hear your prayer. He longs to answer your prayers. He knows because He cares about you. When Jesus came to earth, He came and identified with any possible problem we might face. He has identified with every one of our problems so that He can help us through them. No other god has done that.
5. He forgives us and changes us
When we come to Him and ask for forgiveness, He freely gives it to us. He then begins His changing work in us. Yes, God loves us. He loves us enough to change us so that we don't fall back into our old lifestyle. Are we ever perfect? Nope. Not one bit. But we are being changed continuously. His forgiveness unctions us to change. When we realize how our sin separates us from Him, we want to repent and change. As we are changed, people notice. It affects every part of our lives. We no longer want to live the way we used to.
So there's that. I probably did not do this justice, but it's done. The more I learn about God, the more I realize that there is none like Him.