81 This process, which must be carried forward with prudence and in a spirit of faith, will be assisted by the Holy Spirit. If it is to be successful, its results must be made known in appropriate ways by competent persons. Significant in this regard is the contribution which theologians and faculties of theology are called to make by exercising their charism in the Church. It is also clear that ecumenical commissions have very specific responsibilities and tasks in this regard. The whole process is followed and encouraged by the Bishops and the Holy See. The Church's teaching authority is responsible for expressing a definitive judgment. In all this, it will be of great help methodologically to keep carefully in mind the distinction between the deposit of faith and the formulation in which it is expressed, as Pope John XXIII recommended in his opening address at the Second Vatican Council.
Source: Ut Unum Sint (Vatican.va)