The Bible never claims evil was nessasary. It instead tells us that all that is against God came about by the means of freewill. He essentially didn't want his subjects to be robots.

Perfect beings chose to disobey God - Adam, Eve, and the angel that became Satan the deciever.

The Bible is where it's at. Not the tens of thousands of denominations that all interpret the scriptures differently.

Most Christian beliefs fail because they contradict the Bible itself. Many doctrines that are accepted today were in no way supported by Christ, the apostles, or Gods inspired word.

The Bible, of course, told us this would happen.

"For the time will come when people will not put up with sound doctrine. Instead, to suit their own desires, they will gather around them a great number of teachers to say what their itching ears want to hear." - 2 Tim 4:3