Dialogue is a Christian virtue when it means peaceful discussion, honest, patient listening and learning from others. A dialogue between convinced Christians and believers of other religions is possible, insofar as Christians are willing to speak peacefully about their faith with others (“always be ready to give a reason for the hope that is in you but with meekness and respect”, 1Pet 3:15) and listen to others (Jam 1:19). They wish to learn from others’ experiences in many aspects of life (see esp. the Book of Proverbs) and are willing to call themselves and their behavior into question.
Dialogue is also in important part of working towards peace in a society, as Paul commands us: “If it is possible, as far as it depends on you, live at peace with everyone.” (Rom 12:18), following Jesus’ blessing: “Blessed are the peacemakers, for they will inherit the earth.” (Mat 5:5)
But dialogue which surrenders Christianity’s assertion of truth or abandons world missions is inconceivable, for it gives up Christianity itself. Dialogue which requires the Christian to temporarily or principally waive the claims of absolute truth about Jesus Christ (John 14:6), the Gospel (Rom. 1:16-17, 2:16) or the Word of God (2Tim. 3:16-17, Heb. 4:12-13, John 17:17), so that Biblical revelation is equated with the beliefs of other religions or world views, cannot be reconciled with Christian missions or with the essence of Christianity itself.
Christianity’s assertion of authority is above all expressed in the doctrines of the Last Judgment and of Eternal Life. Hebrews 6:1-2 describes the ‘resurrection of the dead, and of eternal judgment’ as two of the six most important elements of our faith, and as the Apostolic Creed says, ‘he will return to judge both the quick and the dead’. At the same time it is God himself, who will be the judge, and not us, and he has postponed this judgment for a long age of grace, of which we are ambassadors of love and grace, not of judgment.
As humans we only can see the outward appearance, but God alone can see the hearts of men (1 Sam 16:7). This is why he alone has an absolute just judgment taking into account everything you can know about a person.