Often the squeakiest Christian wheel in an environment will be the one that does more harm than good by its noisy profession of faith. Be it a workplace, a family, a neighborhood, or even a church, the voice that speaks of God without a corresponding life that reflects His presence and working does far more harm to the cause of Christ than the most strident and vocal atheist.
In the workplace, for example, the believer who seeks to genuinely influence people for the Lord Jesus will understand that before he utters a word, the determination must be made that he will be the hardest working person on the job. He will show up on time, he will not miss work unless providentially hindered, his attitude will be kindly and cooperative, he will respect both his supervisors and fellow workers, and he will not inappropriately or abruptly seek to speak of Christ when his mind should be focused on the endeavors of the workplace. Indeed, he will seek far more to speak by his life than his words, taking opportunities clearly orchestrated by the Holy Spirit for witness, but recognizing that these will be far more effective by emphasizing quality rather than quantity.
The same principle applies in every environment. Recalling that the word "witness" in the New Testament is translated from the same Greek root word as "martyr" will go far in helping us to realize that a self sacrificial life and attitude speaks of the Lord Jesus no less eloquently than the finest oration. Certainly we seek and expect opportunities to bear verbal witness for Christ, but not before we have devoted ourselves to God for the applied witness of a life well lived by the true leading and power of the Holy Spirit. Indeed, the squeaky wheel never bears appeal, driving people away rather than leading them unto the Savior who Himself lived long before He spoke.
"We are not as many, which corrupt the word of God: but as of sincerity, but as of God, in the sight of God speak we in Christ."
(II Corinthians 2:17)