A constant and voluntary sinful life kills it, as it were.
It is impossible to mortify one's conscience. She will accompany a person to the Last Judgment of Christ: there she will denounce her disobedient.
According to the explanation of the Holy Fathers, the rival of man mentioned in the Gospel is conscience [877].
Exactly: she is a rival! because he resists every unlawful undertaking of ours.
Keep peace with this rival on your way to heaven, during your earthly life, so that he does not become your libeler while your eternal fate is being decided.
The Scripture says: "A faithful witness shall deliver the soul from the wicked" [878]. A faithful witness is an immaculate conscience: it will deliver the soul that hearkens to its counsel from sins until death and from eternal torment after death.
As the blade of a knife is sharpened by a stone, so the conscience is sharpened by Christ: it is enlightened by study and refined by the fulfillment of the Gospel commandments.
A conscience enlightened and refined by the Gospel shows a person in detail and clearly his sins – even the smallest ones.
Do not do violence to your opponent – your conscience! Otherwise, you will be deprived of spiritual freedom: sin will captivate you and bind you. The Prophet laments on behalf of God about those who trample on their consciences, who slander themselves: "Ephraim overcame his rival, trampled down judgment, for he began to walk after the vain ones" (879).
The edge of conscience is very tender; It must be stored and stored. It is preserved when a person fulfills all the requirements of conscience, and the violation of any requirement, due to weakness or infatuation, is washed away with tears of repentance.
Do not think of any sin as unimportant: every sin is a violation of the Law of God, an opposition to the will of God, a violation of conscience.
From trifles, from seemingly insignificant sins, we gradually pass to great sins.
"What does this mean? Is this sin great? What kind of sin is this? This is not a sin! — this is how the one who cares about his salvation thinks when he decides to eat the food of sin forbidden by the Law of God. Based on such an unfounded judgment, he constantly tramples on his conscience.