The following is excerpted from "How Many Doors?" by Ken Ham:
Just as Noah and his family had to go through a door to be saved, so we must go through a door (i.e., the Lord Jesus) to be saved. Jesus is the only Ark of Salvation for us to receive eternal life with our Creator.
[The] authority is the Bible—God’s Word. God tells [us] in His Word that "unless one is born again, he cannot see the kingdom of God" (John 3:3). We’re also told in Romans 10:9 "that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved."
So, whether you’re a Baptist, Catholic, Presbyterian, Moslem, or Hindu—if you’re not born again as the Bible states, and have not received the free gift of salvation in Christ, the Bible clearly teaches you will not spend eternity in heaven with our Creator and Savior. You will be in hell separated from God—forever.
“Jesus said to him, ‘I am the way, the truth, and the life. No one comes to the Father except through Me’” (John 14:6).
“Jesus said to her, ‘I am the resurrection and the life. He who believes in Me, though he may die, he shall live’” (John 11:25).
“I [Christ] am the door. If anyone enters by Me, he will be saved” (John 10:9)
Thus, the Bible clearly teaches there is only one way, only one door, to heaven, Jesus Christ.
 Copied from: http://arkencounter.com/