36. Nor are difficulties lacking within the People of God; indeed these difficulties are the most painful of all. As the first of these difficulties Pope Paul VI pointed to "the lack of fervor [which] is all the more serious because it comes from within. It is manifested in fatigue, disenchantment, compromise, lack of interest and above all lack of joy and hope." Other great obstacles to the Church's missionary work include past and present divisions among Christians, dechristianization within Christian countries, the decrease of vocations to the apostolate, and the counterwitness of believers and Christian communities failing to follow the model of Christ in their lives. But one of the most serious reasons for the lack of interest in the missionary task is a widespread indifferentism, which, sad to say, is found also among Christians. It is based on incorrect theological perspectives and is characterized by a religious relativism which leads to the belief that "one religion is as good as another." We can add, using the words of Pope Paul VI, that there are also certain "excuses which would impede evangelization. The most insidious of these excuses are certainly the ones which people claim to find support for in such and such a teaching of the Council."
In this regard, I earnestly ask theologians and professional Christian journalists to intensify the service they render to the Church's mission in order to discover the deep meaning of their work, along the sure path of "thinking with the Church" (sentire cum Ecclesia).
Internal and external difficulties must not make us pessimistic or inactive. What counts, here as in every area of Christian life, is the confidence that comes from faith, from the certainty that it is not we who are the principal agents of the Church's mission, but Jesus Christ and his Spirit. We are only co-workers, and when we have done all that we can, we must say: "We are unworthy servants; we have only done what was our duty" (Lk 17:10).
[Pope John Paul II, Redemptoris Missio]