Because there are many religions in the world today and it is understandable that folks can easily become confused. If we genuinely want to know the truth we must look to the Bible, God's Word in order to know how to get to heaven.
We read in Romans 10:8-13 " ... the word of faith, which we preach; That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.... For whosoever shall call upon the name of the Lord shall be saved. "
You must personally believe that Christ shed his blood for your sins on the cross and that he rose again so that you can be "saved" (To be "saved" means that you no longer have to go to hell, you have been given eternal life and have been provided with the only way to go to heaven).
Remember that it is not through a church or by baptism or by good works (Ephesians 2:8 & 9 "For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast."), but by faith in what Jesus Christ has already done.
The most wonderful knowledge in all this world is to know that you are going to heaven.