Lumen Gentium 16

"Nor is God remote from those who in shadows and images seek the unknown God, since he gives to all men life and breath and all things (cf. Acts 17:25-28), and since the Savior wills all men to be saved (cf. 1 Tim. 2:4). Those who, through no fault of their own, do not know the Gospel of Christ or his Church, but who nevertheless seek God with a sincere heart, and, moved by grace, try in their actions to do his will as they know it through the dictates of their conscience--those too may achieve eternal salvation."