5 Those who go astray from the road wander far from the goal they aim at. Similarly, if the pure and true light of truth be rejected, men's minds must necessarily be darkened and their souls deceived by deplorably false ideas. What hope of salvation can they have who abandon the very principle and fountain of life? Christ alone is the Way, the Truth and the Life (John XIV., 6). If He be abandoned the three necessary conditions of salvation are removed.
Source: Tametsi Futura Prospicientibus (Vatican.va)