J.I. Packer, On the Sovereignty of God and Our Evangelism

“You are not on a fool’s errand. You are not wasting either your time or theirs. You have no reason to be ashamed of your message, or half-hearted and apologetic in delivering it. You have every reason to be bold, and free, and natural, and hopeful of success. For God can give His truth an effectiveness that you and I cannot given it. God can make His truth triumphant to the conversion of the most seemingly hardened unbeliever. You and I will never write off anyone as hopeless and beyond the reach of God if we believe in the sovereignty of His grace.” (Evangelism and the Sovereignty of God)