I hope I approach this delicately since I know this is common language used to describe the relationship Christians have with Jesus Christ. To be honest, I don’t know how this terminology originated but I believe it is a more recent phenomenon. While I know this to be a widely embraced concept that relates the presence of the Lord with us, I want to reconcile how this fits with in terms of the nature of God, and specifically how this relates to the Christian’s union with Christ.
It is essential for Christians to understand God’s character and works according to his triune nature. God is one yet operates at all times interdependently as three distinct persons. All activity of God is according to the Father’s will. The Father sent the Son so that God could be fully revealed to humanity (Colossians 1:19; 2:9). The incarnate Son of God took on humanity such that he was fully God and fully man and gave himself as a living sacrifice so that the righteousness of God may be imputed onto those who believe in Him (2 Corinthians 5:21; Romans 3:21-26).
Prior to his death, burial and resurrection, he informed the apostles that he was going away but that he would send the Advocate, who would be with them just as he was (John 14-16). After the resurrection, he ascended into heaven where he sits at the right hand of the Father (Acts 2:33; Hebrews 1:3; 8:1; 12:2). Union with Christ occurs because the believer is given the Holy Spirit who baptizes us into the kingdom (Galatians 3:27; 1 Corinthians 12:13; Ephesians 1:13-14). The Holy Spirit enables us to accept God’s truths and turn our affection towards him through belief in the Son. The filling of the Spirit (cf Ephesians 5:18) means that the Spirit influences us to live lives of obedience, trust and worship of the one true God. But Christ himself is with the Father.
Michael Patton at Parchment and Pen gives a good explanation of Christ’s presence in this post on the Roman Catholic doctrine of transubstantiation. In refutation of this doctrine, which proclaims that the Eucharist represents the real presence of Christ, one reason he gives is that Christ cannot be true to his nature and present everywhere.
Orthodox Christianity (not Eastern Orthodox) holds to the “Hypostatic Union” of Christ. This means that we believe that Christ is fully God and fully man. This was most acutely defined at the Council of Chalcedon in 451. Important for our conversation is that Christ had to be fully man to fully redeem us. Christ could not be a mixture of God and man, or he could only represent other mixtures of God and man. He is/was one person with two complete natures. These nature do not intermingle (they are “without confusion”). In other words, his human nature does not infect or corrupt his divine nature. And his divine nature does not infect or corrupt his human nature. This is called the communicatio idiomatum (communication of properties or attributes). The attributes of one nature cannot communicate (transfer/share) with another nature. Christ’s humanity did not become divinitized. It remained complete and perfect humanity (with all its limitations). The natures can communicate with the Person, but not with each other. Therefore, the attribute of omnipresence (present everywhere) cannot communicate to his humanity to make his humanity omnipresent. If it did, we lose our representative High Priest, since we don’t have this attribute communicated to our nature. Christ must always remain as we are in order to be the Priest and Pioneer of our faith. What does all of this mean? Christ’s body cannot be at more than one place at a time, much less at millions of places across the world every Sunday during Mass.
Now there have been debates for centuries in terms of the presence of Christ. But I think we need to ask how can the ascended Lord Jesus Christ be seated at the right hand of the Father, does not cease to be fully God and fully man and also live in our hearts.
Well, there is the Holy Spirit. But here we must be careful too. We might think of the Holy Spirit as indwelling our physical bodies like a substance. This is a concept associated with Panentheism, God is in everything. But this is not a Christian worldview. God is wholly other than us. Rather, there’s no space that God’s authority does not touch. For the Christian who has been regenerated and indwelt by the Holy Spirit that means our soul has been made alive to see the beauty of God and respond to him in true worship. God’s presence abides with the believer because of the ministry of the Holy Spirit who impacts us.
For those regenerated by the Holy Spirit, our hearts have been truly touched. But I don’t know that we should say Jesus lives in our heart because it sends a confusing message. Rather, it is the place where his truth abides through his word so what we might place our affections on him.
Let the word of Christ dwell in you richly as you teach and admonish one another with all wisdom, and as you sing psalms, hymns and spiritual songs with gratitude in your hearts to God. (Colossians 3:16)