Truth is simply ‘that which corresponds to reality.’ That is, truth is an expression of the way things are. In that sense, truth is absolute.
Christianity is a belief system based on information: that Jesus is God in the flesh, come to reconcile us to Himself. However, following Jesus is about more than information. "We can only possess what we experience. The facts of theology can be altogether cold... though true in every way, they alone can't change me."