"Test yourselves to make sure you are solid in the faith. Don't drift along taking everything for granted. Give yourselves regular checkups. You need firsthand evidence, not mere hearsay, that Jesus Christ is in you. Test it out. If you fail the test, do something about it." (2 Cor.13:5, The Message Bible) "My purpose in writing is simply this: that you who believe in God's Son will know beyond the shadow of a doubt that you have eternal life, the reality and not the illusion." (1Jo 5:13, The Message Bible) The epistle of 1 John identifies the vital signs of eternal life. They provide a diagnostic tool that will reveal our true spiritual condition. We can accurately test ourselves for the presence, or absence, of eternal life. Also, the strength, or weakness, of each vital sign reveals the quality of our spiritual health and where we need to take emergency action. Calvin Partain was born to parents who were devout believers in Jesus Christ. He was saved in his childhood years. When a senior in high school God made it clear to him that his calling in life was to be a pastor-teacher. His formal training includes the normal College, Seminary, and countless seminars and conferences. But his main preparation for writing this book has come through more than fifty years of serving people as their pastor. Calvin is theologically conservative. His conviction is that the Bible is God's inerrant revelation of Himself to man, written by divinely inspired men. Calvin has been married to his high school sweetheart for over fifty years. God gave Calvin and his wife Marion two sons and a daughter, two grand-daughters and three grand-sons. One son and a grand-daughter are in heaven. "This book is essential for anyone that wants to inventory their own spiritual health, grow greatly in Christ, or nurture others in doing all of the above." Dr. Keith E. Eitel Dean of the Roy Fish School of Evangelism and Missions Professor of Missions Southwestern Baptist Theological Seminary