Why is unbelief such a sin?
Here is my beliefs...It is the only sin that will keep a person from eternal life, according to the Bible. If the Bible is true and we are all sinners (its obvious to me that I am), but God loved us so much he sent his son to pay the penalty of sin (death, he died) so we may be freely saved, and we reject God's only provision for salvation, his precious gift of his own Son who came here and suffered and died for a fool like me, I believe that's not only a serious snub to Almighty God, but we have rejected the only provision he has made to save us,
Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved. Acts 4:12.
Do you really think the claims made in the bible are so convincing that unbelievers must be willfully living in denial to reject it?
God has placed eternity in their hearts, Ecc. 3:11, so everyone, whether they admit it or not cares about how they will spend eternity. God is holy, we are not, we need the righteousness of God freely imputed to us to be able to be with him forever. That's just what the Bible, which I believe is God's Truth, clearly teaches and what anyone's conscience (with knowledge, we know we have done wrong or fallen short of God's holiness), must certainly tell them if they are honest (that God is holy and I am not is a no brainer to me).
Back in the day miracles happened by the truckload (supposedly). Yet today, when a unbeliever asks for a sign he is rebuked. As if asking for evidence for a claim before believing it is wrong. According to the bible people must act like unquestioning, mindless sheep or they are wrong.
Miracles were actually few and far between in the Bible. From the last prophet of the OT (besides John the Baptist), 400 years went by with nothing, same while they lived in slavery in Egypt. The miracles were actually confirmation signs so that when God said something through someone, people knew it was true. Like Jesus healed a man and forgave his sins so they knew by his works that his words were truth. Same with the apostles, they said Christ rose from the dead and did miracles so people believed them. They had the witnesses and wrote it down and now we have that, God's Word of truth and the testimony of many witnesses (not to mention the thousands of changed lives of people throughout history). It would be nice to have some big miracle performed today, but then that wouldn't be faith, would it?
Then believers turn around and try to use the old free will arguement as if it makes any sense, which it doesn't.
I don't know what you mean about the free will deal. I know anyone who desires to be saved can be freely saved without doing anything to earn it or doing anything to keep it or anything in return for it. That sounds pretty good to me.
You can keep your doom day predictions and "great" white throne of judgment. I don't need it.
I don't like dooms day, but it is repeated throughout the Bible over a span of some 1500 years by many different prophets. As God said,
Woe unto you that desire the day of the Lord! to what end is it for you? the day of the Lord is darkness, and not light. Amos 5:18. And I believe it repeats the theme as well, that we will all stand before God and give an account. We will all be standing at that bar very soon. I believe since we have all sinned (I know I have), we are all guilty and the penalty is death, this is not only physical and spiritual, but eternal suffering in the Lake of Fire. But for those who have trusted Christ to have paid the penalty for them and accept his free love gift, the debt has been paid and they are declared justified before God and clothed in His righteousness. That's what I believe. You say to keep it, that you don't need it. That's ok, but I believe we all need Jesus.
MUST is a word used by kings, and the King of Kings said,
Ye, must be born again! That's the only thing we must do in this life to have the free gift of eternal life forevermore, and we don't born ourselves we are born again of God, God does it all, he does the saving, he does the keeping. OK, peace!
20 Now then we are ambassadors for Christ, as though God did beseech you by us: we pray you in Christ's stead, be ye reconciled to God.
21 For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him. 2 Cor. 5