I'm not sure it's helpful to talk about evangelism in terms of percentages, but someone once said that 90% of our witness should be through our actions and 10% should be with our words. Saint Francis of Assisi is credited for saying, "preach the gospel and, if at all necessary, use words." I've always loved the Saint Francis approach but I think that it can become a cop-out. And as long as we're dealing with percentages, that 10% (or whatever percent) where we do use words can be critically important. The fact is, it is necessary to use words. Our words are the bones beneath the flesh of our actions. Words have power, power to mobilize and to challenge, power to transform the environments around us. We are accountable for our words, for their content as much as the mediums and contexts of their delivery. Language is too vital to human interaction for it to be isolated from the life of a Christian, especially since the Christian life is all about human interaction and relationship.
I don't know why it is, but it seems that the church is split--the people who are doing the most Christ-like work are the most timid when it comes to talking about Jesus. The ones who are actually embodying the kingdom of God by standing for the oppressed, fighting for the dignity of the marginalized, living in solidarity with the outcast, and meeting the needs of the "least of these" are the most negligent when it comes to telling the story of God and they're the least likely to invite people into an intentional relationship with Christ. And the very people who are the most vocal about Jesus, the quickest to the trigger when it comes to sharing the gospel, are the same people who side with the wealthy, marginalize the ones who don't think as they think, alienate the immigrant, and are so very disconnected from the "least of these" in their own backyard. Where's the balance? Few are those who are willing to live and speak boldly.
We need to be careful with our words, contextually responsible for what we say. But we have also got to take back evangelism from those who have hijacked and distorted it into a manipulative and conquest-oriented endeavor. Those of us who are more prone to live the gospel without mentioning it, we who are prone to using St. Francis' perspective as a cop-out and a way to avoid speaking the good news of Christ into the lives of the people around us need to train ourselves to actually tell people about Jesus. Perhaps we're embarrassed and afraid to be associated with those who've so manipulated evangelism in the past. But that's all the better reason to do it well and to do it often.
The good news of Jesus should have the effect of transforming the texture of our environments, of giving hope and inspiring endurance. If we found a way to say it well, the gospel would have the same transforming power as our actions of love and justice, even if to a different degree or in a different way.
On the flip side, I'd challenge those who have perhaps overemphasized the importance of speaking. I'd challenge them to read the gospels again and to do what Jesus did. I'd challenge them to connect with the ones in need, to open their eyes to social injustice, and to humbly love all the wrong kinds of people... just like Jesus did. Speaking the gospel is important, as I've already argued, but living it is still vastly more important.