Believer, is there such a thing..if you will..as a 'silent witness?' Isn't that like a contradiction of terms? I'd say there is such a person..but not always silent. Which is more important.. living the life of Christ or explaining the Good News of Christ? I'd say both r rad-important. Living like Jesus did..apart from all truth-communication ain't really enough if u want to be a loving biblical witness! Think 'bout it, even Christ Himself used words of truth and love to be a good Witness of the Good News for His Father. Yes, sinners within reach of Him heard God's Word from Christ's mouth!
Take the time to look at all the Bible says on this topic? Start here...
"Go home to your friends, and tell them what great things the Lord has done for you, and how He has had compassion on you." Jesus, Mk. 5:19
"Preach the Word! Be ready in season and out of season." 2 Tim. 4:2
"How beautiful upon the mountains are the feet of him who brings Good News, Who proclaims peace, Who brings glad tidings of good things, Who proclaims salvation, Who says to Zion, 'Your God reigns!'" Isa. 52:7