Dogmatic Constitution on the Church, Lumen gentium 16:
Those who have not yet received the Gospel are related in various ways to the people of God. In the first place we must recall the people to whom the testament and the promises were given and from whom Christ was born according to the flesh.(Rm 9,4-5). “On account of their fathers” this people remains most dear to God, for “God does not repent of the gifts he makes nor of the calls he issues” (Rm 11,28-29). But the plan of salvation also includes those who acknowledge the Creator. In the first place amongst these there are the Muslims, who, professing to hold the faith of Abraham, along with us adore the one and merciful God, who on the last day will judge mankind.
Nor is God far distant from those who in shadows and images seek the unknown God, for it is he who gives to all men life and breath and all things, (Acts 17, 25-28) and as Savior wills that all men be saved (1Tim 2,4). Those also can attain to salvation who through no fault of their own do not know the Gospel of Christ or his Church, yet sincerely seek God and moved by grace strive by their deeds to do his will as it is known to them through the dictates of conscience. Nor does Divine Providence deny the helps necessary for salvation to those who, without blame on their part, have not yet arrived at an explicit knowledge of God and with his grace strive to live a good life. Whatever good or truth is found amongst them is looked upon by the Church as a preparation for the Gospel. She knows that it is given by him who enlightens all men so that they may finally have life. Continue reading