I discovered this criteria on the internet on July 28, 2007. 

1. Summary of what would have a good chance of convincing a future Christian:
   1. Verified, clear, specific prophecies that could not have been contrived.  They must be verified by at least two or three witnesses.
   2. Miraculous occurrences, especially if brought about through prayer.  Best if verified or from an unimpeachable source.
   3. Any direct, verifiable manifestation of the divine by voice or visions.  Best if verified by several sources.
   4. Aliens who believe in exactly the same religion.
2. Summary of what a future Christian would like to see, assuming direct intervention by a god:
   1. a religion without internal disputes or factions.
   2. Knowledge in that religion's writings that was not available at that time.
   3. a genuinely flawless and consistent holy book.
   4. a religion whose followers have not committed or taken part in any atrocities.
3. Summary of what would be dismissed by a future Christian:
   1. "miracles" that are human origin, natural or coincidental.
   2. people's conversion stories without a good explanation of why they did it.
   3. the Bible code or other numerological feats.
   4. any explanation of creationism or young earth.
4. Summary of things a future Christian often overlooks:
   1. God has an interface for dealing with humans called "promises."  Since He is justice personified, He must be approached through these.  Without them, there is no contact.  The Bible is full of these promises.  Try them out.
   2. Long term prophecies must be non-specific, to keep people from trying to counterfeit it around the time that is supposed to happen. They may try to counterfeit an ancient writing to "prophesy" for their gain as well.
   3. Miraculous occurrences are happening every day in Christian and sometimes in Jewish societies.  The atheist doctors usually discredit supernatural healings with "faulty diagnosis" or "the new drug finally kicked in."  The Christians usually are too caught up with the moment to document the incidents when they pray.  It takes a lot of money to put on a rigorous, scientific study  on healing prayer.  Anti-Christians can dig into major foundations for funds to concoct a "study".  The few rigorous studies done be Christians out of their own pockets are discounted by the phony "studies" and are not given the publication they deserve.
   4. God's voices and visions are usually given to the one person, although angels can be seen by numerous people.  It's not something you can plan ahead and record on tape.  What is said can be verified as being very unlikely to be chance.  Or numerous visions & voices tell numerous unlikely things that come to pass and can give a high confidence factor.
   5. There are aliens from another dimension who can be forced to tell the truth.  They believe in the Judeo-Christian God, that Jesus Christ came and the Holy Spirit of the universe is in charge.  They are called demons, promoting evil, dishonesty and alienation from God.  They have been around for thousands of years. They have mastered how to mislead people and recruit allies.  Some of these allies are even in churches and seminaries, causing mayhem.
   6. The writings of the Christian New Testament are very consistent through the 10,000 texts and scraps that have been found all over the Mediterranean area, giving a high confidence factor - and even shows the very few places where there are some texts that say something a little different.  Half the New Testament was originally written in Hebrew and all we have left are the Greek translations.  And now the Greek has been translated into all the languages of the world by very careful translators. Synonyms and homonyms in the Hebrew, Greek and other languages leave open the chance for misunderstandings. Entropy happens.  But it is not enough to corrupt the basic teachings in the New Testament. We respect the Jewish old Testament because Jesus Christ our Lord did, but it is not the basis of our faith.
   7. Good and evil can coexist because of god's "mercy."  This is only postponed justice for all humans and angels, since we all are under the same sentence.  Inevitably, justice will come to pass to the last speck.  Fortunately, God himself came up with a loophole in his own law to save us from the judgment -- a Messiah.  Since he is God and also human, only humans can use this loophole in the law by becoming one with Him.  But only our supernatural soul is saved.
   8. Experiences of death and coming back to life can't be repeated, isolated or verified by science.  Anyone who had a time near death can say anything they want.  But there are people who saw verifiable things near where there body was and then went on out of this dimension and had further experiences.  The first part tends to verify the second.
   9. Current science is disprovable at any time.  The methodology covers a small minority of occurrences.  Beyond those, the religious writings may be more accurate.  There is a lot of opinion and dishonest research that is being called "science"  that has no foundation in real science.  Today, Science is being milked for all of its respectability by giant corporations and governments for giving credibility to their lies.  Lab coats and graphs don't guarantee Truth.
   10.  The Atheist says, "We are open minded."
       Answer: We have been inculcated with the elements of atheism in government schools, with the assumption that each individual will have a contrived Epiphany when they connect the dubious dots given them in school. Because of the Epiphany effect, they will claim it as their own, making it difficult to show them another world view.  But we can pray that God will give them a real Epiphany.