Jesus said that those who are pure at their very core are the ones who will see God. In 1 John, we see the promise of the beatific vision: "See what kind of love the Father has given to us, that we should be called children of God; and so we are" (1 John 3:1a). John introduced this section of his epistle with an expression of Apostolic amazement. The thing that is so incredible and astonishing is that people who are not pure in heart are adopted into the family of God. We simply do not qualify for that relationship in terms of our own character; nevertheless, we are called the children of God.
John goes on to say:
The reason why the world does not know us is that it did not know him. Beloved, we are God's children now, and what we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is. And everyone who thus hopes in him purifies himself as he is pure (3:1b-3).
People often have questions about what things will be like in heaven. What will we be like? Will we know each other? Will we appear to be the same age that we were when we died? Or will we have glorified bodies that somehow are ageless? How will we occupy our time? We are always puzzled by these things, and John was puzzled too, for he said, "What we will be has not yet appeared." We are given glimpses of what heaven will be like, but we don't have a complete picture of what to expect when we cross over to the other side. John was cognizant of the limits of our knowledge, and even the limits of the revelation that he received about these matters from the Lord, but He doesn't leave us groping in the darkness. We don't yet know what we will be like, but this much we do know: we will be like Him, that is, Christ.
Elsewhere, when the New Testament speaks about the consummation of Christ's kingship at His return, it uses the language of apocalypse, which means "unveiling." At this point, Christ will be made manifest; He will appear in His full glory. When the Bible speaks about seeing Him again, we are told that when He appears in this unveiling, we will see Him; every eye will behold Him. So the force of these passages should direct our attention to the hope of seeing Christ in the fullness of His glory.
The theological definition of the Trinity says that the Father, the Son, and the Holy Spirit are three in person, but one in essence or being. This truth promises something even greater, if that's conceivable, than seeing Christ face-to-face in the fullness of His glory. We won't simply see the expression of the perfect image of God; we will see God in His very essence, face-to-face. Obviously, this poses a difficult philosophical and theological question: If God is a spirit, how can the Bible speak of seeing Him in the purity of His essence, when His pure essence is spiritual and invisible?
Jonathan Edwards had some interesting thoughts on this question. His thinking is certainly speculative, but it gets me excited when I think about it. We put great stock in being an eyewitness; someone will say that something is true because he saw it with his own eyes. We know how important physical sight is, and what a blind person would give to have his sight restored. So, we must have functioning eyes to see, as well as a brain that correctly interprets the images. But the ability to see is not enough; we need light. We can't see in the dark. Edwards suggested that the experiences that we think of as direct and immediate eyewitness experiences are really indirect and mediated experiences. They pass through the intermediate steps of light, sensation, nerve stimulation, and so on. According to Edwards, the ultimate vision of God will be one that takes place without the eyes. It will be a direct and immediate apprehension by the human soul of the very essence of God—a completely and dramatically transcendent mode of perception. All of the barriers that prevent our seeing God will be removed, and we will be filled in our souls with direct, immediate apprehension of the being of God.
Jesus said, "Blessed are the pure in heart, for they shall see God." The thing that keeps us from having the vision of God now is our impurity, our sin. John said that when we see Him, we will be like Him, for we shall see Him as He is. The question remains as to whether God will glorify us in heaven, allowing us to see Him as He is, or whether He will show Himself to us, which will purify us. We don't know the answer to that, but it's interesting to think about, because nothing would be a greater agent of purification than a direct, immediate vision of the nature of God. John said that even the promise of this future vision works to begin our purification right now. So, keep it always in front of you as the ultimate promise for the fullness of your soul.