Sin became visible as weeds and infectious yeast. Hypocrites were poisonous snakes. We can see whitewashed tombs. We can smell putrid flesh. Note the way that effective preachers such as Billy Graham use true stories and illustrations.
Human interest is an essential part of the mix.
So testimonies can be a key part of an evangelistic web-site. Call them true stories, life experiences, case studies, or something similar. The book of Acts records Paul telling of his own conversion three times. No doubt he told it many more times in his ministry. Because the audience are not Christians, their interests and viewpoint are totally different.