The beatific vision is the fulfillment of Jesus’ promise that we will see God. That is the essence of it. Then, we have to ask, “What does Jesus mean by seeing God?” We have to say that it is not a matter of physical sight for the simple reason that God is invisible. He is the invisible God. Many Christians tend to think that when we die, we will see God because He will become visible. However, He is not going to change because we die. This is the sheer mystery of His being. He is not the kind of being who is in His own nature visible. But, He makes Himself visible.
John Calvin has a beautiful way of speaking about creation as the invisible God putting on the clothes He wears to go outside so that we can see what He is like. I think that is part of what it means for us to see God. We see Him in this world, and we will see Him more fully in the world to come.
The main way we are to think of the beatific vision is God has made Himself visible in the most perfect way that human beings are capable of apprehending, that is, in Jesus Christ. For example, the New Testament speaks about seeing the glory of God in the face of Jesus Christ. One way I love to put it is in John 1:1, which says, “In the beginning was the Word, and the Word was with God.” The language John uses here is like the idea of being face to face with God. The beauty of what John says here is that the Son who was face to face with the Father has now become face to face with us. So, we see in the Son’s face the reflection of the beauty, glory, and marvel of God’s being.