“But he who is joined to the Lord is one spirit with Him.”

In Spirit

My personal view of “in spirit” or “spiritual” is the opposite of the secular or popular view.
The popular view is of something ghostly and insubstantial, or unreal, related to a psychological state. That view would interpret this verse as saying, “We may be one with the Lord emotionally but maybe not in practice.”

My interpretation of “spiritual” is to be truly real, and include all of reality that is not visible to the limited human eye; e.g. most of the electromagnetic spectrum was invisible to us until a couple of hundred years ago, and the first radio communication must have appeared like witchcraft to ordinary folk. And current scientific theory tells us that 95% of the universe is not visible even to radio waves.

To under-value and ignore the spiritual is like a person seeing the outside skin of an apple, and saying “that’s all there is”, and never looking within to receive its delicious nutrition.

Unity with the Lord

The depth to which we are “one with the Lord” is shown in Romans 6:3-5, “Or don’t you know that all of us who were baptized into Christ Jesus were baptized into his death? We were therefore buried with him through baptism into death in order that, just as Christ was raised from the death through the glory of the Father, we too may live a new life. If we have been united with him like this in his death, we will certainly also be united with him in his resurrection.”

In this chapter, this unity is contrasted with being united with the things of this earth that lead to death. The example given in verse 16 is prostitution and sexual immorality, but it also applies to everything that would detach us from our unity with Jesus, to things that would unite us, or enslave us, to sin.

Personal application

Prostitution may seem easy to ignore, but I can think of loads of things that present other temptations in my life – concerns about money, love of cars & housing, TV and entertainment, and hobbies that I had hoped to immerse myself in full-time in retirement.
But the fact that I haven’t been able to do much of those hobbies is a source of encouragement. What gets in the way is opportunities to care for the people God brings into my life – such as helping my elderly neighbour, giving time for my mother and brother when they have needed care, and helping with technical developments at church.