Not a lost cause, my friend. Not a lost cause at all.
This too will pass away, and the truth of natural law created by God will be recognized as the truth it is once again.
And every little (or big) effort any of us make on the side of the light of truth will give us light as well. Whatever good is done to serve the truth will light our own way. Good in the service of God's truth is never in vain, never unnoticed by Him, and who knows how many individuals have been helped by your efforts, or mine?
We may feel insignificant or useless sometimes, but each soul reclaimed is a victory.