I suppose there are a lot of great religions. But what is a "religion"? To me, it's a bunch of rules and rituals. If we look through history we can find where some people have made up a new religion to believe in.
I think a person can also be religious about anything. We use the word "religiously" to show when someone is fervent about something. But being fervent or religious about something doesn't necessarily make that something truth.
I've been called "religious" at times. I try not to take it as an insult. People who have called me religious mean well--they mean that they know I'm a Christian and that it is very important to me. But I don't consider myself religious.
I am a Christian. I've looked at the evidence, and I'm totally convinced it is true. There are no rules to follow to make me "good enough" with God.
There are definitely no rituals. Oh, we do some things in church and what not, but none of them are required to make us right with God.
Religion is all about ritual. Christianity, on the other hand, is all about reality.
“Paul then stood up in the meeting of the Areopagus and said: ‘Men of Athens! I see that in every way you are very religious. For as I walked around and looked carefully at your objects of worship, I even found an altar with this inscription: TO AN UNKNOWN GOD. Now what you worship as something unknown I am going to proclaim to you.’” (Acts 17:22-23, NIV)
And then Paul went on to tell them about the One True God, the Creator of the world and everything in it, and of His Son Jesus Christ whom He raised from the dead.