My main answer to you is very simple:  If one of those dead religions had been true, then I very strongly believe that God (or goddess, or gods, depending on the religion) would have preserved it and not allowed it to die out.  I can't imagine that God (or gods or goddesses) would give a true communication to humans through a religion and then allow it to be completely forgotten.

As far as existing religions go, I'll say this.  I became a believer in God about 3 and a half years ago.  I did not immediately go to Christianity.  I feel that God wants us to worship Him according to His true character, and in order to find out which religious text (if any) described who God actually is I listened a huge number religious texts in audio.  The God that I had experienced was perfectly characterized in the Bible.  Bare in mind that I was very unfamiliar with the Bible, nor was I even subconsciously in line with its principals or characterization of God (for the most part, and I did examine myself fairly.)

I don't take God's character lightly.  I was sure to explore every alternative with an open mind and an open heart.  Without an open mind and an open heart, the believers of Jesus' time would have never accepted Him.

On top of this, I will provide another very strong evidence (proof in my opinion) for Christianity's validity.  All of the 10 of the 11 apostles who claimed to see and speak with the resurrected Jesus were martyred (john, the brother of james, was the only one who died a natural death - and he still faced hardships due to his claims.)  These men were not acting based on a religion that someone had told them about, they were acting based on something (the resurrected Jesus) that they claimed to have saw.  They either truly saw Jesus resurrected, or they had created a lie.  I find it very unlikely that 10 men would be willing to go to their graves based on a story that they had made up.  Also we have paul who claimed to have seen the resurrected Jesus on the occasion where he was struck blind.  He lived a difficult life and spent a great deal of time in prison before he was eventually put to death.  Again, I don't believe he would have gone through all that for the sake of a vision that he made up.

Also, we have the fact that Christianity was heavily persecuted for the first 300 years of its existence yet it grew like crazy.  No other religion that I'm aware of began in such a way.  Most religions grew in their infant years by governmental force.  Christianity was exactly the opposite, it grew in spite of a government that was very hostile towards it.  It did not become accepted by the government until the year 313 AD.  Christianity continues to grow in countries like china in a very similar fashion.  Pbs, which is hardly a pro-Christian channel, did a documentary called "Jesus in china" on Christianity's amazing growth in the officially atheist nation of china which you can watch for free on their website (http://www.pbs.org/frontlineworld/stories/china_705/video/video_index.html) I believe that in order for the religion to have grown in the way that it did, the hand of God had to have been the driving force.

Might I ask a question?

If I sin (as I'm told everyone does either through physical action or thought crime). If I do not accept Jesus into my life and ask unconditionally for forgiveness etc, Am I condemned to eternal hellfire?

Because the concept that someone will have eternal punishment for finite limited sin is morally bankrupt.

Any God that supports such eccessive eternal punishment is worthy of contempt in my mind.

I hope thats not it, because as I said, such a concept seems extremely immoral.

fairy tales I tell you,fairy tales. leaves thread. lol