As one who in essence is writing letters, I come to understand what made those that wrote the letters to the churches do what they did. Mainly they were separated by distance. In at least two cases the one writing the letters was imprisoned and unable to go to those they were writing these letters that later become the New Testament.
In my case I am unable to travel to those that have read my post due to obligations that require me to stay where I am. In several cases I am incapable of travel to them since at this time I have reached fifty two nations; one or two of them I never thought I would ever see that they have bothered to read that I have written but they have. Some come back time to time and look once again at what has been added. Most likely, many never return, but that is ok. At least once they read something that may have impressed upon them something that will come back to them in some other way. This is how God works at times. Planting little tidbits here and there, within their minds, till one day one of these seeds sprout and spread the love and joy of God throughout them. They realize that if not me than someone or something made them understand and accept God. Then they turn to His Son Jesus Christ and become saved.
I encourage and challenge those that are reading at this very moment to go pick up and Bible and read it. Learn the teaching of Jesus. Try to understand that they are still as relevant as they were when He first spoke them. Yes start with the New Testament but then turn to the Old and read it as well. For everything within the Old points to the New and to Christ.
2 Timothy 3:16 All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: 17 That the man of God may be perfect, thoroughly furnished unto all good works.