Acceptance of all Catholic teaching. Assent must be both internal, in our own mind, and also external, proclaimed to the world through our actions.
Vatican II’s Lumen Gentium, Dogmatic Constitution on the Church, § 25, states:
This religious submission of mind and will must be shown in a special way to the authentic magisterium of the Roman Pontiff, even when he is not speaking ex cathedra; that is, it must be shown in such a way that his supreme magisterium is acknowledged with reverence, the judgments made by him are sincerely adhered to, according to his manifest mind and will. His mind and will in the matter may be known either from the character of the documents, from his frequent repetition of the same doctrine, or from his manner of speaking.
The Vatican’s Congregation for the Doctrine of the Faith, in Donum Veritatis, Instruction on the Ecclesial Vocation of the Theologian, May 24, 1990, § 23, teaches that every Catholic must give assent to the Faith at three levels:
”When the Magisterium of the Church makes an infallible pronouncement and solemnly declares that a teaching is found in Revelation, the assent called for is that of theological faith. This kind of adherence is to be given even to the teaching of the ordinary and universal Magisterium when it proposes for belief a teaching of faith as divinely revealed.”
”When the Magisterium proposes ’in a definitive way’ truths concerning faith and morals, which, even if not divinely revealed, are nevertheless strictly and intimately connected with Revelation, these must be firmly accepted and held.”
”When the Magisterium, not intending to act ’definitively’, teaches a doctrine to aid a better understanding of Revelation and make explicit its contents, or to recall how some teaching is in conformity with the truths of faith, or finally to guard against ideas that are incompatible with these truths, the response called for is that of the religious submission of will and intellect. This kind of response cannot be simply exterior or disciplinary but must be understood within the logic of faith and under the impulse of obedience to the faith.”