We admire the cosmos with its billions of stars and atoms. Most learned people say that the cosmos shows God's being and goodness. The creatures are weak images of the infinitely perfect qualities of God. Human mind can know the abstract ideas and the properties of God, and is undecayable.
All humans have a conscience, all peoples have a religion. Deep in his heart, everybody knows that God rewards goodness and punishes evil. But this doesn't very often happen here on earth. Each human strives for complete happiness, but doesn't find it on earth. But if God didn't want to make us perfectly happy, He would not have created us.
From the foregoing, we already know that heaven exists. Many saints appeared after death to the people they loved. They answer our prayers and do miracles for our salvation. The appearances of virgin Mary are best known. So seeing God doesn't paralyze our human abilities, but makes them perfect.
After the Last Judgment, we will be reunited with our glorified bodies. All creation will be glorified. There is no more evil and no more suffering. The soul is the master of the body (impassibilitas, claritas, subtilitas, agilitas). We will see through ourselves and our lives on earth. Our senses will give us unspeakable joys. Many saints do supernatural perceptions and miracles in their lifetimes already. For instance, Gemma Galgani saw her guardian angel.
Unbaptized people can belong to the soul of the Church by their good will. Our pains and trials help us to choose for God. God Himself has become man to save us. He took our sins and our sufferings on His shoulders. His empire is not in this world. We need the virtues of belief and hope and love. Prayer helps us to obey the commandments.

I prefer the tridentine Mass, if possible. In summer I can cycle for hours, and I can go to Liege by train. But in Maastricht we have beautiful old churches, if only offering the new Mass.
We can exaggerate everything. There are many people who seclude themselves to pray forever, decrying and leaving alone with their difficulties the people who need them, and thinking that it is easier to go to heaven this way.
You have to be careful with mortifications as well. It is important to maintain good habits. However, to achieve that, you must reward yourself. Of course, these rewards must not become another bad habit.
The Gospel is a good message. It wants to give people hope, not to make them afraid. Life is difficult enough. But we still have