God gave his only son that all who believed in Him might be saved, for God did not send his only son into the world to condemn it, but to save it, that all may have salvation. (Paraphrased John 3:16-17)
Salvation is God's free gift to all who accept Jesus Christ, but only those who accept Him and His Son are allowed into Heaven. It's not hard, people. God gave us Jesus, who lived a perfect and blameless life to be the blood sacrifice that washed away all of our sins. That way we can be saved and live in Heaven with Him in fellowship for eternity.