The following is from Got Questions Ministries:
Will more people go to heaven or to hell?
The question of whether there are more people in heaven or hell is answered by Jesus Himself in one succinct passage: “Enter by the narrow gate. For the gate is wide and the way is easy that leads to destruction, and those who enter by it are many. For the gate is narrow and the way is hard that leads to life, and those who find it are few” (Matthew 7:13-14).
This passage tells us that only those who receive Jesus Christ and who believe in Him are given the right to become children of God (John 1:12). As such, the gift of eternal life comes only through Jesus Christ to all those who believe. He said “I am the way, and the truth, and the life. No one comes to the Father except through me” (John 14:6). It’s not through Islam, Buddha, or other false gods of man’s making. It’s not for those wanting a cheap and easy way to heaven while continuing to live their own selfish and worldly lives on earth. Jesus only saves those who fully trust in Him as Savior (Acts 4:12).
Read more: http://www.gotquestions.org/more-people-heaven-hell.html
"I don't believe in Heaven or Hell."