Before I became a Christian, I thought I already was one. Whenever I was in trouble, I cried out to Jesus. I thought I must surely be a Christian because I was praying. But I did not understand what being a Christian really was.
When the chips are down, most people do pray. It has been said, "There are no atheists in foxholes." If your life is on the line, you will pray. I think back on my own life and recognize that whenever trouble hit, I would call on God. I would pray, "God, if you get me out of this crisis, I promise I will serve You. I will do whatever You ask me to do." He would get me out of that one and I would say, "Thanks, God. See you next crisis." So in a sense, you could say that I prayed. But my prayer life consisted of moments of crisis when I called out to God out of fear.
In the Book of Jonah, we find the story of a great storm that arose on the sea. We read that all the sailors on the ship with Jonah began to call on their gods. That is what people will do. They will call upon their god when they are in trouble. But that doesn't mean God is necessarily living in their lives. It's possible to pray and not even know the God you are praying to.
If you are a Christian, you should certainly pray. But praying does not necessarily mean you are a Christian. You need to have a personal relationship with God. You need to believe in Jesus Christ and follow Him.