What verse says we are responsible to testify to the truth? I can't comment on it without the context.
John 18:48
“Pilate therefore said unto him, Art thou a king then? Jesus answered, Thou sayest that I am a king. To this end was I born, and for this cause came I into the world, that I should bear witness unto the truth. Every one that is of the truth heareth my voice.
So in this context testifying to the truth would be telling people that Jesus is the truth and preaching about who He is etc.
We are responsible to preach the Gospel of Jesus Christ. Many christians today have gotten caught up in current event arguments and are thinking that their calling has become to stand against things they don't like going on in the world.
That never has been our calling or our message. Out message is still the same. Jesus Christ, the same yesterday, today and forever. That is what we should be known for preaching after we are gone. Those who remember us should remember that was our only message. And it applies to every age no matter what is going on in the world.
Too many christians are getting caught up in conspiracy theories, and then turning them into twisted ideas about the strategies of satan that we are supposed to be fighting against and all their conversation is about earthly temporal things like masks, and mandates, and vaccines, and not about the Gospel of Jesus Christ.
It is a disturbing trend. While they are "standing up" and fighting against something they don't agree with that they have personified as evil that they are supposed to resist, they are all the while falling for the trap that satan has laid for them, and they are speaking with anger, bitterness, venting and fomenting hate, calling politicians they don't agree with by disparaging names and making a fool of themselves and discrediting their witness of the character a Christian should possess.
Then later when they try to share the gospel with someone that knows them, that person they are speaking to is not believing that they have actually experienced this freedom from anger that they say Jesus can give, since they have witnessed so much of it in that persons life over current events in the news.
Well, that is a very big subject that deserves a thread all to itself. However, let me just say that we are to speak the truth in love, to have an answer for everyone who asks, the reason for the hope that lies within us. We are to make the good confession, to bear true witness when someone's life and reputation are on the line. These things are all biblical.
But you make a very good point. The art of speaking truth in the right spirit and with the right perspective is critical if we are to have a good Christian witness. If we speak about lofty things that challenge our limited education and experience we should speak with humility, prepared to adjust our thinking. There's nothing wrong with speculating, or asking. I think it's a responsible thing to bring Christian truth into every area of our society.
For example, if we don't address the issue of crime, Christianity will seem to have no answers, and will leave things vague and lacking truth. If we don't speak to politics or foreign affairs, how are people to judge the issues, lacking the ability to apply Christian truth to each situation?
But number one, we have to have the right attitude, with charity and humility. And secondly, we must study to show ourselves approved, ensuring that we have the right facts. There's no problem addressing issues with an incomplete knowledge if we're humbly trying to discover all the facts.
I've found that a few central Christian truths help me to apply Christian truth to politics and to society. One, we are to judge things by separating the Christian society from the secular society which may be mixed Christian and pagan. Christian truth applies differently within Christian society than it does within pagan society.
We cannot back our country's foreign policies if they aren't truly Christian. We can support the Christian parts they do. But we cannot support the things about those foreign policies that are not Christian.
Also, we must accept by necessity submission to flawed political establishments. We do not have to approve of it in order to properly submit to an order that has been established by God. I would have to address each issue separately if I'm to be more clear on this.