If it is true, as they say, that one is known by the company he/she keeps, then the first epistle from the Apostle John is really good news for Christians. 

In the prologue of this letter John talks about Christian Fellowship.  He tells us that, if we are in Christ, not only do we have fellowship with other Believers, but with God Himself!   

In the following verses John explains how we experience that fellowship. That’s what he is talking about when he writes about “walking in the light…” (See v. 5-10) 

John begins by talking about God: “God is light; in Him there is no darkness at all. 

John is here succinctly expressing a few important things.   

1.      Theology is important.   

Theology, in the proper sense, is the study about God.  And John demonstrates here that theology, at its best, is practical.  For John, knowledge of God is not an optional accessory for the Christian life; theology is not something that is left for the professionals.  Theology comes first, as a foundation upon which we build our lives, our churches, and our relationships. 

2.      Fellowship begins with considering God.   

John has already expressed that his purpose in writing about our fellowship is “to make our joy complete.”  Here, again, he elaborates about how we experience that fellowship – and he begins by talking about God. 

Wisdom, true spirituality, and real fellowship (that produces joy) always begin with our understanding of who God is. 

This may seem obvious to most of us. But, as Dr. Martyn Lloyd-Jones suggests:  

“Most of our problems occur precisely because we don’t begin at this point.” 

3.      God is Holy 

J.I. Packer says: “Those who know God have great thoughts of Him.” 

John describes God as being “light”.  Again, it is helpful to remember that John uses word pictures to help us grasp concepts that are important but difficult to define. 

By describing God with the metaphor light, John opens us to consider a wide range of God’s attributes. But while “light” may illustrate many of God’s attributes, most scholars seem to agree that what John has in mind, primarily, is God’s holiness. 

Recognizing, and contemplating God’s holiness is essential to having a relationship with God, and according to John understanding God’s holiness is important for our relationships with others.  

For more reading about God’s Holiness, I suggest: 

Holiness of God by R.C. Sproul 

The Knowldege of the Holy   by A.W. Tozer