Atheism and unbelief
What does the Church say about people who do not believe?
"Many . . . of our contemporaries either do not at all perceive, or explicitly reject, this intimate and vital bond of man to God. Atheism must therefore be regarded as one of the most serious problems of our time." GS 19 # 1.
The name "atheism" covers many very different phenomena. One common form is the practical materialism which restricts its needs and aspirations to space and time. Atheistic humanism falsely considers man to be "an end to himself, and the sole maker, with supreme control, of his own history." GS 20 # 2. Another form of contemporary atheism looks for the liberation of man through economic and social liberation. "It holds that religion, of its very nature, thwarts such emancipation by raising man's hopes in a future life, thus both deceiving him and discouraging him from working for a better form of life on earth." GS 20 # 2.
Since it rejects or denies the existence of God, atheism is a sin against the virtue of religion. Cf. Rom 1:18. The imputability of this offense can be significantly diminished in virtue of the intentions and the circumstances. "Believers can have more than a little to do with the rise of atheism. To the extent that they are careless about their instruction in the faith, or present its teaching falsely, or even fail in their religious, moral, or social life, they must be said to conceal rather than to reveal the true nature of God and of religion." GS 19 # 3.
Atheism is often based on a false conception of human autonomy, exaggerated to the point of refusing any dependence on God. Cf. GS 20 # 1. Yet, "to acknowledge God is in no way to oppose the dignity of man, since such dignity is grounded and brought to perfection in God...." GS 21 # 3. "For the Church knows full well that her message is in harmony with the most secret desires of the human heart." GS 21 # 7.
Agnosticism assumes a number of forms. In certain cases the agnostic refrains from denying God; instead he postulates the existence of a transcendent being which is incapable of revealing itself, and about which nothing can be said. In other cases, the agnostic makes no judgment about God's existence, declaring it impossible to prove, or even to affirm or deny.
Agnosticism can sometimes include a certain search for God, but it can equally express indifferentism, a flight from the ultimate question of existence, and a sluggish moral conscience. Agnosticism is all too often equivalent to practical atheism.
"Since Christ died for all, and since all men are in fact called to one and the same destiny, which is divine, we must hold that the Holy Spirit offers to all the possibility of being made partakers, in a way known to God, of the Paschal mystery." GS 22 # 5; cf. LG 16; AG 7. Every man who is ignorant of the Gospel of Christ and of his Church, but seeks the truth and does the will of God in accordance with his understanding of it, can be saved. It may be supposed that such persons would have desired Baptism explicitly if they had known its necessity.