I Corinthians 5:10 covers the fact that Carl Sagan most likely knows God's truth by now, whether or not those who are still living believe it. The only way that he doesn't is if the proper understanding of scripture is that Mr. Sagan is in a waiting situation until we all face God at one time.
As for judging others, I would be curious to know what it is in your copy of the Bible that leads you to believe that we are not allowed to know right from wrong when we see them. The only times I've ever heard anyone try to argue that "judging others" was sinful was when they took Matthew 7:1 out of the Bible because it suited their purpose, of trying to silence those who recognized their sin, and denied almost the entirety of the rest of the Bible. Using the same type of so-called logic and the same level of intellectual honesty you could just as well declare that it is a sin to split wood. "What God has put together, let no man put asunder." You can take any scripture in the Bible or any other book of any religion or any human creed of evolution or...well you get the idea... choose a choice phrase that you think makes a point that you want made and completely ignore the reality of what the text you pulled it from says. Congratulations you now qualify to be a mainstream journalist by todays standards. However if you want to have some intelligent discourse with people who will respect you enough to consider what you say, you would be far wiser to stick to your chosen texts rather than warp them in that way (and just not choose a book that doesn't really make the point you want made).
It's not as if you are addressing someone who considers the biblical texts to be either accurate or authoritative. As such you are free to disregard whatever remarks issue forth as if to accuse those who understand where the texts came from and what they mean. It's like a student lecturing a teacher: one doesn't wonder that it's done with fervor, but rather that it is done at all.
Fixed it.