There is a great importance in the Christian life to actually speak and actually use words. There is a lot of truth in wisdom that people will be attracted to Jesus by the way we live.
But the reality is that we will often need to speak words to help people see reality as it is. Of course the righteous life will be of great use to help our words make sense to those we speak.
The reality though is that very few people are converted by life alone. Christianity is a message not a mystical experience and the only way to communicate the message is through words.
The reality is that if we love others then we may at times have to be open to share our faith. There is a great amount of discomfort that can come with this.
But a few of the many comforts are here for us when we share Jesus: this world is not our home, only the opinion of God matters in the end, and God can use even a humble expression of faith to help others.
For a post discussing how eloquence can disguise the truth look here.
eloquence which is evil