i have had several debates with some kids at my school who have made the decision to become atheists. most of their arguments consist of science disproving the bible. i need some help on were i can acquire the knowledge to further debate them.
Cool. What you are interested in is called apologetics. It comes from the Greek apologia which means defense. Although I do agree with several of the others that it depends on what they are arguing, here is a basic argument.
First Cause/Kalaam Cosmological Argument
Premise 1: Everything that begins to exist has a cause
Evidence: This is simply a casual relationship. Everything that BEGINS must have a cause in our universe due to the constraints of spacetime.
Common Objections:
Q: Why doesn't God have a cause?
A: The theistic understanding is that God is eternal and does not have a beginning. Ergo, Premise 1 does not apply to God
Q: What about "virtual particles?"
A: Virtual particles require space time to exist so, in essence, they have a cause and exist within space and time.
Premise 2: The universe began to exist
Evidence: Mathematical proof by Guth et al proves that universes such as ours come from a single point when spacetime is equal to zero. "Before" that "time" the universe did not exist.
Common Objections:
None really as most atheists accept the Big Bang Theory
Conclusion: The Universe has a Cause
Furthermore: To prevent infinite regression there must be some Uncaused Cause. This Uncaused Cause must be powerful enough to create the universe and is outside spacetime and therefore eternal. It is this Uncaused Cause that we call God.
For more arguments/good reading see...
Mere Christianity by C.S. Lewis
On Guard: Defending Your Faith with Reason and Precision by William Lane Craig