given the second testament via Jesus then, for a Christian, the Old Testament should be meaningless.
The New Testament is a comforter for the Jews who realized that Jesus was the suffering messiah.
The comforter they had in reminding themselves of the whole gospel story and the amazing things Jesus taught them were at first told by the witnesses, and set down in writing @ 54AD.
But the Old Testament is the very source for what Jesus revealed.
Jesus said "I am the truth," and he meant, truth about what the Old Testament is telling us, as opposed to the Rabbi and pharisees of his own day.
He also meant in a larger sense, that he personified Truth, itself, and the natural opposition to the Truth by men in general.
His message was to do as the Torah says, by facing the Truth about what it is we and the Jews then were really doing.
Much like the Catholic of today who "confesses" of Saturday and pays a tithe on Sunday, but returns again next week to the same vices, the Jews had become fixated in their same bad behavior in spite of offering up their sacrifices of barley, doves, and lambs.
Jesus was facing down the forces that maintain a culture that does what it wants, while preaching otherwise.
We saw the Christianity of Truth at work in 1965 when Rev Martin Luther King stood for the Truth when it was unpopular.