It’s no surprise that you find you can’t get a straight answer from anyone on this question, because everything about life after death is basically a mystery. We don’t have a blueprint, a map or a photograph of heaven. Life with God is beyond our human imagination’s ability to conceive. Our imagination is rooted in our earthly experience of time and space and life with God is without time and is not limited by space–which is what we mean by the word “eternal.”
However, our imagination can give us hints or clues, based on our experience in this life. My favorite definition of hell is that of the Russian novelist Dostoevksii that “hell is the suffering of being unable to love.” If this is true, then heaven must be the happiness of being able to give and receive love. The first letter of John tells us that “God is love, and whoever remains in love remains in God and God in him” (I John 4:16).
If this is the case, then we learn how to be in heaven by opening our hearts to receive and give love. Jesus in Matthew’s gospel tells us that we will enter heaven if we give food to the hungry, clothe the naked, care for those who are ill, and visit those who are in prison (Matthew 25:31-45). These actions of compassionate service to others aren’t “brownie points” that we must earn, but rather ways of opening our heart’s capacity to love. In the same way, selfish choices or holding on to bitterness and resentment can shut down our heart’s ability to love easily, much as other muscles atrophy when they aren’t exercised.
Heaven is not something that begins for us only when we die. We can taste its presence in the inner peace we feel when we choose to live our lives with and for others. This peace can be present even when the outer circumstances of our lives are wracked by difficulties. One way to describe heaven is as a giving of ourselves over to the mystery of God. That process doesn’t wait for death, it begins for us in this life.