Probably, the greatest advocacy for the Gospels is the JW publication: The Greatest Man that Ever Lived. It convinced me.
Everything else that the Bible says about the resurrection and eternal life logically follows.
The testimony of a “witness” in Court matters only if it is observation not commentary ( expert witness is also commentary): What did you see, What did you hear, What is the magnitude of your measurement. Not, are you convinced; that is only belief. Although evidence and testimony are convincing to the mind, one can only know for a fact by observation, experience and measurement. When studying the Gospels, a person can become convinced but to know anything at all, the person would need direct evidence from God—a taste to actually witness about.