The two main themes of today's passage revolve around Truth and Love, and how Love is reflected in how we treat others.
I found vs 2 of chapter 1 John 1 interesting relative to truth. We often think of truth as an inanimate or factual verbalization, yet we are reminded that truth is a living breathing thing which lives in us and should manifest itself in our everyday lives. Christ and his spirit are living and breathing within us and as a result our lives should manifest this.
The commands about love are present in the old testament where we are told to "love our neighbor as ourselves..", Here John is writing to the body of believers and makes specific mention that they love one another. Do we truly love our fellow believers, or do we smile when we see them, yet hold a grudge for something that was once said or a wrong we felt was done against us? It is a command- Walk in Love. To be effective for Christ and be considered "walking in the truth", love for our fellow believers in critical.
The challenge for me from 3 John was with respect to love and support for those who have given up their own lives to spread the gospel (aka missionaries). We are challenged to show hospitality (and support) as we are partners with them in their work. The personal challenge for me over the holidays is to connect somehow with one of our church missionaries and help meet a need they might have.
Truth and love are two words that we hear frequently tossed about in today's world, yet if truth and love do not originate in Christ...they are merely words.