The source of your confusion apparently stems from a misunderstanding of predestination and foreknowledge. Predestination is never mentioned in the Bible.
However, there are numerous instances where something has been pre determined by God, based on his foreknowledge.
1st. Samuel 25:17 Now therefore know and consider what thou wilt do; for evil is determined against our master, and against all his household: for he is such a son of Belial, that a man cannot speak to him.
this was destined by God because of his foreknowledge, that David would make war with Nabal, and David was saved from killing Nabal by Abagail, who would also have perished had David and his men attack Nabal's household. However the LORD himself killed Nabal.
1st. Samuel 25:38 And it came to pass about ten days after, that the LORD smote Nabal, that he died.
Daniel 9:19 through 24 O Lord, hear; O Lord, forgive; O Lord, hearken and do; defer not, for thine own sake, O my God: for thy city and thy people are called by thy name.
20 And whiles I was speaking, and praying, and confessing my sin and the sin of my people Israel, and presenting my supplication before the LORD my God for the holy mountain of my God; 21 Yea, whiles I was speaking in prayer, even the man Gabriel, whom I had seen in the vision at the beginning, being caused to fly swiftly, touched me about the time of the evening oblation. 22 And he informed me, and talked with me, and said, O Daniel, I am now come forth to give thee skill and understanding. 23 At the beginning of thy supplications the commandment came forth, and I am come to shew thee; for thou art greatly beloved: therefore understand the matter, and consider the vision. 24 Seventy weeks are determined upon thy people and upon thy holy city, to finish the transgression, and to make an end of sins, and to make reconciliation for iniquity, and to bring in everlasting righteousness, and to seal up the vision and prophecy, and to anoint the most Holy.
At the beginning of thy supplications the commandment came forth, and I am come to shew thee; for thou art greatly beloved: therefore understand the matter, and consider the vision. God sent Gabriel to Daniel for the express reason of explaining the future to him the future is therefore known to God, and was so before Creation.
The fact that God knows the future does not mean that he has decreed every thing to happen in a specific manner, which what predestination means.
God gave man free will and he has the choice of his eternal future, If God had predestined what souls would and would not be saved it would no longer be free will as those destined for Hell would not have the option of salvation, and those destined for salvation would not have the choice of disobedience.
We cannot fathom why God decided to go ahead with creation and especially the creation of man knowing that many would choose to spend their eternity in torture. To Question God and his ways is no different than Satan's sin in that it is elevating our principles to be equal with his.
Hope this helps