Soteriology is branch of theology that deals with salvation. This is important because it impacts our presuppositions towards the sovereignty of God and his relationship to man. In the Bible, clearly it teaches that God saves people, however, what is disputed is how God goes upon doing it. In the Bible there are some peculiar words that are use that have divided Christians for centuries concerning how God saves people, words like foreknew, and predestined. The two different views on how God saves people are Arminianism and Calvinism which we will be looking at briefly.
Arminians hold to the view that man has a libertarian free will-- that can choose contrary to their sinful natures-- enabling them with the help of the Holy Spirit to choose to accept or reject God's offer of salvation. They believe since God is Omniscient ( he knows everything) he has predestined those who will choose salvation.
Calvinists hold to the view that man is dead in his sins (Eph 2:1), radically corrupted, and a slave to sin (Romans cpt 6). Man does not have a libertarian free will rather a compatiblist will, so he can make choices but only according to his sinful nature, therefore he cannot choose God. God must by his Sovereign will and prerogative regenerate a sinner dead in trespasses by his irresistible grace which cannot be refused. It is like God raising a man from the dead without his permission (Like Jesus raising Lazurus). Calvinists believe that the Bible teaches God predestines people to salvation according to his good-will and purposes (Eph 1:11, Romans 8:29-9:33) not because of future knowledge of them willfully accepting salvation with their free will. Calvinists hold that if God predestines people because of their choice then those that choose not to accept salvation are not predestined because they did not do something that the predestined people did. They did not meet the condition in order to be predestined. Calvinist would conclude that if God predestines people because of their choosing to believe in him man is saved by works and grace which is in direct contradiction to what the Bible teaches that man is saved by grace alone to the Glory of God (Eph 2:8-9, Titus 3:5, Rom 11:6). The question that would deduce from what Calvinists believe is why does God save anybody? the answer is we all have a wicked heart (Jer 17:9) and are sinners deserving justice which is hell, but God for his Glory has chosen to save some people by the substitutionary death of his son Jesus Christ. But who are we to question God and his divine wisdom and counsel?