Let me start with preaching and teaching on hell. There are two aspects of this discussion. The first is that there are some people who are living in hell now on earth. They may know this. Drug addicts who are sick and dying, those depressed with porn, the greedy, who have realized their lives are empty. Those who know they are in hell do not need hell preached to them, but life. The Light of the world, Christ, will bring them the life which these desperate people know is gone from their lives. Therefore, they are open to life, because they are aware of death.
However, the vast majority of people who have chosen some evil, such as adultery, homosexual sex, fornication of any kind, drunkenness and gross consumerism do not know they are living in hell because they are living in a bubble of deceit they have created for themselves.
The man who has affairs and says he cannot live without sex is lying to himself, The woman who has had several abortions in order to keep her high-flying job is lying to herself about life and the meaning of sex. Those who want more and more things, and have not reached the saturation point of lust and greed lie to themselves about what brings true happiness.
All sinners who do not convert lie about consequences. To those who are not desperate, talking about hell is a good teaching tool. Discussing hell must be a wake-up call for some.
As to preaching heaven, only those who believe in heaven and who are fed up with life on earth as they have made it would be open to this Good News of salvation
Discussing God and His desire that we spend eternity with Him in heaven is also good time spent with believers who need to work on perfection.
Again, as I have written in the past, we need to walk away from those who are persistently closed to the Good News and bring God's beautiful plan for salvation to those who are open.
Only the Holy Spirit can open hearts and convert. We only plant seeds and nurture growth, but to avoid discussing the afterlife is avoiding the deeper discussions of the need for Salvation and the Incarnation. We must preach the Gospel to the world as we are commanded to do so by Christ.
His words are not a suggestion, but marching orders.
Mark 16:15New Revised Standard Version Catholic Edition
15 And he said to them, “Go into all the world and proclaim the good news to the whole creation.
All are born in Original Sin. Those who are baptized no longer have Original Sin. Again, there is a difference in those who are baptized and those who are not. We are changed in baptism. We become children of God and heirs of heaven.
The saints "capitalized" on the graces given to them in baptism. Now, too many people, the lapsed Catholics especially, squander those graces, like dropping a treasure into the ocean instead of using it.
Saints cooperate with grace. Those who chose evil, and finally, damnation, do not.
Pray, think, reflect, act..Today's first reading at Mass clarifies our position.
1 John 2:12-17New Revised Standard Version Catholic Edition
12 I am writing to you, little children,
because your sins are forgiven on account of his name.
13 I am writing to you, fathers,
because you know him who is from the beginning.
I am writing to you, young people,
because you have conquered the evil one.
14 I write to you, children,
because you know the Father.
I write to you, fathers,
because you know him who is from the beginning.
I write to you, young people,
because you are strong
and the word of God abides in you,
and you have overcome the evil one.
because your sins are forgiven on account of his name.
13 I am writing to you, fathers,
because you know him who is from the beginning.
I am writing to you, young people,
because you have conquered the evil one.
14 I write to you, children,
because you know the Father.
I write to you, fathers,
because you know him who is from the beginning.
I write to you, young people,
because you are strong
and the word of God abides in you,
and you have overcome the evil one.
15 Do not love the world or the things in the world. The love of the Father is not in those who love the world; 16 for all that is in the world—the desire of the flesh, the desire of the eyes, the pride in riches—comes not from the Father but from the world. 17 And the world and its desire are passing away, but those who do the will of God live forever.