DOES IT REALLY MATTER WHAT YOU BELIEVE
The answer is - It means everything what you believe. Your eternal destiny depends upon what you believe. A lot of people say "It doesn't really matter what you believe as long as you are sincere," but that is not actually the truth. There is a popular phrase nowadays that says, "Just believe, just have faith". But the question is - believe what or have faith in who. The what is a saviour from sin, and the who is Jesus Christ.
The bible says to believe on the Lord Jesus Christ is the only way to Heaven.
John 14:6: Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.
Mark 1:15: And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.
Repent means agreeing with God that you are a sinner who needs mercy and to believe the gospel of how Jesus died for our sins and rose again the third day for payment for them. Believing this, you then put your trust in Jesus and receive him as your very own savior.
John 3:16: For God so loved the world that he gave his only begotten son that whosoever believeth in him should not perish but have everlasting life.
John 3:36: He that believeth on the Son hath everlasting life: and he that believeth not the Son shall not see life; but the wrath of God abideth on him.
Notice how it says that he who doesn't believe on Jesus, the Son, has the wrath of God abiding on him. So you can see, therefore, how much it does matter what you believe. It's a matter of eternal life or the eternal wrath of God.
John 20:31: But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
God's Simple Plan Of Salvation
Peace love and blessings to you and your family,
John Michael