Kreeft the apologist gives us good reasons to believe that heaven is necessary for us. It is our true home. He shows us that restoring our faith in heaven will bring us joy even in this life. If our life's work is getting to heaven, he reminds us that we will take life in this world very seriously. Far from neglecting this life, we want to make the world a better place because life in this world is a preparation and pale reflection of the life to come.
But getting to heaven does not depend on our efforts. We need grace, supernatural life. Without Christ, there is no hope for heaven.
Belief in heaven is important for our moral life. If we do not believe that we will meet God face to face, then there is no good reason to be good. Virtue makes sense only if there is immortality.
This is a wonderful and clear explanation of heaven and our need to go there.