Theology is an interaction.  First Arius gave a theological interpretation on the role of Christ and God.  Second the leaders of the Church considered it carefully and came up with their decision.  Then Arius did not accept the decision.  He then was removed and excommunicated or cut off from the communion of the Church.  This problem led to discussion and consensus.  The lived faith in the worship service experience led to a consensus about the most appropriate expression.  The final result was the Nicene Creed, the oldest and most important creed.  Most dogmas came out of disputes.  Over the last two thousand years there have been many more disputes within Christianity.