For it to be relevant, they do. It would be much easier insofar as avoiding disagreement if everyone just said "oh, if you say so, it must be true". That wouldn't be honest and would be solely done to avoid conflict. I don't want people saying they agree with my views just to shut me up.
If your saying that your don't believe in God, then I don't agree with you at all, and I can't make you agree with me and I don't intend to try to do so. Jesus told us to speak the truth and God will judge us on what we hear. We're not hear to force God's word onto others but rather bare witness to the truth.
Jesus didn't force anyone to believe, he brought us the truth through the gospel, and we have a choice, believe or not. I'm just trying to show you why I do believe and how I can't understand how others can't see that there has to be a greater mind behind creation!
To me, out of everything around us, even just the sun alone shows us that God exists, it is burning constantly and never runs done, what can make something burn over all that time, to me, there has to be a greater mind over everything.
Although I don't just believe God exists, I know he does as I've had proof in my life. So I know he's there. But I'd never force my beliefs on anyone, even my own family. I speak the things of God and live it out and Jesus teaches and then they have a choice to make too. But I pray always for them that they will believe the truth.