81 Dialogue, therefore, is a recognized method of the apostolate. It is a way of making spiritual contact. It should however have the following characteristics: 1) Clarity before all else; the dialogue demands that what is said should be intelligible. We can think of it as a kind of thought transfusion. It is an invitation to the exercise and development of the highest spiritual and mental powers a man possesses. This fact alone would suffice to make such dialogue rank among the greatest manifestations of human activity and culture. In order to satisfy this first requirement, all of us who feel the spur of the apostolate should examine closely the kind of speech we use. Is it easy to understand? Can it be grasped by ordinary people? Is it current idiom? 2) Our dialogue must be accompanied by that meekness which Christ bade us learn from Himself: "Learn of me, for I am meek and humble of heart." (56) It would indeed be a disgrace if our dialogue were marked by arrogance, the use of bared words or offensive bitterness. What gives it its authority is the fact that it affirms the truth, shares with others the gifts of charity, is itself an example of virtue, avoids peremptory language, makes no demands. It is peaceful, has no use for extreme methods, is patient under contradiction and inclines towards generosity. 3) Confidence is also necessary; confidence not only in the power of one's own words, but also in the good will of both parties to the dialogue. Hence dialogue promotes intimacy and friendship on both sides. It unites them in a mutual adherence to the Good, and thus excludes all self-seeking. 4) Finally, the prudence of a teacher who is most careful to make allowances for the psychological and moral circumstances of his hearer, (57) particularly if he is a child, unprepared, suspicious or hostile. The person who speaks is always at pains to learn the sensitivities of his audience, and if reason demands it, he adapts himself and the manner of his presentation to the susceptibilities and the degree of intelligence of his hearers.
Source: Ecclesiam Suam (Vatican.va)