Go and follow the light

When we say that one should learn from the experience of one’s life whether Christianity is the truth of life, this does not demand anything which is beyond us. It simply tells us: ally yourself with what is genuine, with the challenging, with what demands everything, with the courage to accept the mystery within you. It simply tells us: go on, wherever you may find yourself at this particular moment, follow the light even though it is as yet dim; guard the fire even though it burns low as yet; call out to the mystery precisely because it is incomprehensible. Go, and you will find — hope and your hope is already blessed interiorly with the grace of fulfillment.
Anyone who sets out in this manner may be far from the officially constituted Christianity; he may feel like an atheist, he may think fearfully that he does not believe in God — Christian teaching and conduct of life may appear strange and almost oppressive to him. But he should go on and follow the light shining in the innermost depth of his heart.

Karl Rahner, “Thoughts on the possibility of belief today,” in Theological Investigations (1966)