Should you hide the Gospel from others if it aids their salvation?

Bit of an odd one question, but it came to me while reading Mere Christianity. In the book, it is discussed that for a treacherous, malevolent person to abstain once from tormenting somebody, that might be worth more than the many daily good deeds of an inherently good man who upholds Christian morality with ease.

It is essentially the idea that true acts of righteousness come from choosing good despite one’s capacity for evil. I reckon that plays into why the repentant thief was saved. This idea also extends to knowledge of one‘s own sin. We judge less harshly a teenager who masturbates and fornicates, because they are are in general less aware of sin (or the gravity of it) and the teachings of God.

We also look more leniently to those who do not know about Christianity. Someone who has rarely if ever heard of Christianity is not expected to have gone to mass, take communion, or repent. In effect, their capacity for evil is far higher (as they have not received the Good News); good acts, which might pale in comparison to a pious Christian, will have more significance.

This brings me to the following question: should we avoid spreading Christianity to prevent that person from understanding sin? Or for those who are already Christians, should we avoid explaining the gravity of sin, such that they may be saved by their ignorance?

As an example: if I have only heard that if I believe in Jesus Christ and be kind, generous, and forgiving that I will be saved, why should somebody tell me that fornication is a sin? Obviously, that person will be condemned by withholding Church teachings from me. However, if I become knowledgeable about sexual sin, I might now struggle immensely with it and lose salvation through my awareness of that sin.

If I care for the salvation of the masses over my own individual salvation, then it would be in my interest to let them sin ignorantly. As if I listed the gravity of all the many sins (and you can basically be sinning 24/7), then it might turn people away from the faith due to the immense weight on one‘s conscience or the difficulty of abstaining from all the sins of earthly pleasure.