If I had to distill the message of Christianity to as few words as possible, I would say that yes, there is a God, inconceivably higher and more complex and powerful than us who authored the universe. He is the origin and example of concepts we have like truth, justice, goodness, and love. Unfortunately, though he is perfect, we are not. The gulf between our imperfection and his perfection is so great that we can't even look upon him and live, and he would be perfectly just to snuff out the life he gave us.
But the good news is that it doesn't have to be like this. Through the death and resurrection of Jesus God made a way for us to know him, the infinite creator, personally, at no cost to us. Because of this relationship our lives are transformed and we change to live more like Jesus.
So the message of Christianity is really that it's more than a message, it's a relationship. If I could leave you with anything, it would be to try and look past all the denominations, all the politics, all the tradition, all the debate, all the hypocrisy and sin of us Christians, to try to understand that relationship. None of it makes sense without that.