The Bible says in Romans 6:23, "For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord." Because of our sin, we do not deserve to spend eternity with God when we die.
Jesus came to this earth and paid the price of our sin by His death on the cross. John 3:16 says, "Whosoever believeth in him should not perish, but have everlasting life."
We must believe by faith that Jesus is the only way to Heaven. "Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me." (John 14:6)
We are saved by the grace of God. "For by grace are ye saved through faith: and that not of yourselves: it is the gift of God." (Ephesians 2:8) You can receive this free gift of eternal life by calling upon the name of the Lord and trusting Him as your only way to Heaven. "For whosoever shall call upon the name of the Lord shall be saved." (Romans 10:13)