thing that all the atheist's fail to recognize is...
(Romans 8.19) For one mans disobedience(Adam) many were made sinners, so also by one Man's obedience (Jesus) many will be made righteous.
All we need do is understand that Jesus was born from the virgin birth (you heard all the Christmas carols about this time of year), believe he was Gods son, and was raised from the dead by God, in order to receive forgiveness of sin caused by our inherent carnal nature.
(see Romans 10.9)
its not that hard to get your head around, just that most of us are to busy or distracted by the daily grind of life, to put any effort into seeking God, in our lives. Try opening a bible once or twice a week and have some alone time with God.