Witnesses of Jesus were what the apostles were.
The name Jesus is a transliteration of the Hebrew "Joshua" (which is why you find Him occasionally referred to as Yeshua by people of Jewish background who have become Christians). The Hebrew word Joshua means 'Jehovah is salvation', hence the meaning of Jesus name savior. Matthew 1:21 (King James Version) 21And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins. The meaning of His name is also clear from the purpose for which He came, the purpose of which He was Himself aware and which He carried out on the cross of Calvary and sealed with the glorious resurrection. Jesus is the anglicised form of Jeshua, 'The Lord is salvation.