In Christian theology (using our model of Trinitarian Theism) tradition is the fossilized fruit of the best of our thinkers in the past. I believe tradition, however good, must always be checked and reevaluated by study of the Bible. Experience keeps forcing us to re-evaluate (or confirm us in) the theological model and the traditions we have lived by in the past.
Reason is the use of logic to understand and explain the inner structure of a model. Logic can be used to see how another model works, and so help us contrast it with our own. But logic only works within a logical system - it cannot prove that another model is wrong by some superior logic.
For example logic could question the inner structure of say the Taoism
of Lao Tzu. We can also compare the result of living that way with learning
to love by the Holy Spirit. But there is no way we can use Logic to prove
that Creative Love Theism (the model I live by) is right and Taoism if
wrong. They are certainly very different in their outworking.