I would say the central theme in the books of 1 John, 2 John and now in 3 John have been how, as believers in Christ, we should show the love of God to the world in which we live. By doing so we are being obedient to God and we are showing non-believers what an awesome God we serve. In loving others unconditionally, we show them a God that loves them unconditionally.
In the passage of scripture above, John gives us some great examples of ways to show this love and also of things that we should not do as they get in the way of loving others and of loving God.
John speaks of a man named Diotrephes. Diotrephes caused great strife in his church as he would not receive or support traveling brothers and sisters in Christ. During this time in the early church, it was a very common practice to take in traveling preachers and missionaries, so for one in the church to refuse to do this would be very distressing.
Diotrephes' problem was that he wanted to always be first. And, it's hard to be first when we are caring for and supporting the work of others, isn't it? He wanted the glory... not to give it to others by supporting those traveling and sharing the Word of Christ. In his desire to be first, he would:
~ Refuse to receive or support traveling church leaders
~ Maliciously attack those church leaders, discrediting their character and ministry
~ Forbid people in the church from receiving or supporting any church leader, except himself by implication
~ Put people out of the church if they supported these church leaders
As Christians, we should run far away from these types of actions as it is the exact opposite of what God wants of us. Instead, we should always be supporting and receiving others into our homes. We should always support with our kind words instead of spreading malicious untruths.
In the last few verses of this passage of scripture, John gives us three principles to always remember in showing Christian hospitality:
~ Do not imitate what is evil but what is good
~ Always be teachable
~ Strive for consistency in your life
It can be so difficult to show Christian love and hospitality in the world we live in today. However, we must remember that this is what God calls us to do. He knows it is hard... He knows we are criticized... He knows it "interrupts" OUR plans. But, He helps us to make it easier.... He comforts us and helps us to put aside our hurt feelings when criticized... and He always has better plans than those we had that were "interrupted".