One of the big "buzz words" in religion in recent years has been "witnessing." We hear of "witnessing for Christ," "being a good witness," and living so that others can see our witness.
I know a number of people who have objected to the idea of "witnessing for Christ." Their main objection is that nobody today can be a valid witness of anything that Christ did or said. The apostles and other New Testament writers could be witnesses because they lived at the same time as Jesus. Unless a person is 2000 years old they can't be a legal witness. Their testimony is only second hand at best.
On the other hand, most of those who use the term are talking about being a witness not of what Jesus did while he lived as a man on the earth, but what Jesus has done in their lives. Of that they may be valid witnesses, or they may not. If one has not "put on" Christ as the Galatians did, through immersion in water (Gal 3:27), or has not been raised from that immersion to a new life (Romans 6), then their witness could possibly be challenged. They may be able to witness as to the value of living a more moral life, but can not be a witness to the salvation Christ offers, never having availed themselves of Christ's blood.
On the other other hand, even those who object to the term often use it about some who did not know or see Jesus personally. It is in this sense that I sometimes wonder whether I, or others, would be willing to "witness." This is the sense that goes back to the original Greek word for witness, the word we call "martyr." There are a lot of people who are willing to live like Christ … up to his last week. They will tell people about Christ. They want to be witnesses in the court of public opinion. If the witness had to suffer the punishment of the person for whom they were witnessing, though, we might have second thoughts.
Eusebius tells of some of these witnesses/martyrs. There were those that were torn by wild beasts. Some had each limb tied to an animal and were pulled apart. One I find particularly difficult to say whether I could endure was the man who was suspended upside down over a fire that was fed with green wood. He slowly died from smoke inhalation, not to mention a massive headache from all the blood rushing to his head. He may not have said a word, but his witness spoke loud and clear.
There is no doubt that many modern "witnesses" would resist "unto blood" (Heb 12:4). There are also probably many, as there no doubt were in the first centuries, who would be "witnesses," but might balk at being "martyrs." God commends the former, but condemns the latter. "And Jesus said unto him, No man, having put his hand to the plow, and looking back, is fit for the kingdom of God." (Lk 9:6)
"Now if we be dead with Christ, we believe that we shall also live with him…Likewise reckon ye also yourselves to be dead indeed unto sin, but alive unto God through Jesus Christ our Lord." (Rom 6:8,11) What he wants is for us to die first, then we will be witnesses that don't require a subpoena to force our testimony.