Predestination is a needlessly contentious topic in the Church. Much like the Trinity, it is a topic beyond our capabilities as humans to understand. However, just like the Trinity, Predestination is a Biblical fact. As Christians, it is not our job to fully understand everything. Rather, we are to trust God with all our hearts, leaning not on our own understanding (Proverbs 3:5). That being said, the word of God also gives understanding to the simple (Psalm 119:130). So, let us attempt to think Biblically about Predestination.
A major point of contention is what role we play in our own salvation. It is an indisputable Biblical fact that we cannot save ourselves. We are saved by grace through faith, not of works (Ephesians 2:8-10). But some people contend that if salvation is based on faith, we are therefore contributing to our salvation. Effectively, it all boils down to whether or not faith is a work. Let's use another doctrine to demonstrate why this is not the case.
In the beginning, God created the heavens and the earth. God created two people, Adam and Eve. I believe I am a descendant of these two people, meaning I am a creation of God. Now, does believing God created me get me any credit what so ever for my own existence? Of course not! God gets all the credit, I simply believe.
Let's use another, more personal example. I own a cross necklace. This necklace was made by a friend of mine, who we'll call Layla, and was sent to me as a Christmas gift. Now, I didn't ask her to make me a necklace. I didn't want her to make me a necklace. I didn't make the necklace. I didn't pay a shipping fee for the necklace. Even when she told me a surprise gift was coming, I didn't know it was specifically a necklace coming. In other words, there is no possible way I can be credited for the ownership of my necklace. All I did was receive it with all gratefulness. The necklace, rather than being something brought about by my own hand, was a gift.
And that's what salvation is: A gift (Romans 5:15-18, 6:23). It is not a gift we wanted. It is not a gift we asked for. It is not a gift we made, or paid for. When the Messiah was prophesied, it is not even a gift the faithful fully understood. All the work that made salvation possible was done by Jesus. Now, it's on us to receive it like the gift it is.
Salvation, as a gift, is something God wants for everyone. He takes no pleasure in the death of the wicked (Ezekiel 18:32; 33:11), and He wants no one to perish, but rather He wants all to come to repentance (2 Peter 3:9). But as much as we know God wills to save everyone, we also know that, unfortunately, He isn't going to, and indeed many have perished already. This is where Predestination comes in. Man cannot choose God unless God first chooses him (John 6:44). None of us seek God (Romans 3:11). So, God, in His infinite wisdom, chooses whom He will save, and whom He will allow to perish.
To some, this seems like a harsh concept. God chooses whom He will allow to perish? Effectively, God chooses who to send to Hell? Harsh though this may seem at first, it should be noted (and this reinforces the point that we get no credit what so ever for our own salvation) is that God owes all of us His eternal wrath. God is not obligated to save a single person from Hell, and so the fact that there will actually be multitudes that no one can count in Heaven (Revelation 7:9) is just staggering.
But how does God choose that multitude? We know that God doesn't play favourites (Deuteronomy 10:17), so how does He choose who will be saved, and how does He ensure they come to faith? The answer is in God's foreknowledge.
In His omniscience, God is able to tell the end from the beginning (Isaiah 46:10). God knew, even before the world began (Ephesians 4:1) who would and would not choose Him, and how to make us choose Him, so Romans 8:29-30 tells us that we, whom He foreknew, He predestined, and so He called us to salvation. And in true, self-fulfilling fashion, this is how He ensures the predestined will be saved.
We actually see a rather sad example of this in the cities of Tyre, Sidon, whom Jesus said would have repented. If He had done His miracles there instead (Matthew 11:21). Verse 23 indicates that Sodom would also have repented had Jesus done His miracles there. Notice, Jesus didn't say "if I'd predestined them, they would have repented". No, He put forward the repentance that never came as a response to His miracles. In other words, He knew what it would have taken to cause them to repent. He simply didn't give them that push.
And this is why we cannot come to the Son unless we are drawn in by the Father. We cannot choose something about which we do not know. It is ignorance that makes us incapable of repenting, like how Paul persecuted the Church in ignorance (1 Timothy 1:13-15). But God knew ahead of time how to make Paul repent. He foreknew Paul, and so He predestined Paul, and so He called Paul. And this is how He does it with everyone (Romans 8:29-30).
But obviously, Paul was a special case. Not everyone starts their journey to faith killing Christians only to meet Jesus on the way to kill even more. No, we all come to faith in other ways. The Bible tells us that faith comes through hearing, and hearing through the word of God (Romans 10:17). By contrast, you can't believe in what you've never heard (Romans 10:14). So, the purpose of God's word is to make us wise to salvation (2 Timothy 3:15), causing us to come to faith. We also know that God's word achieves the purpose for which it was sent out (Isaiah 55:11), and that God can actually achieve the good works He has planned for us without us (Esther 4:14). Even if every single Christian on earth was too lazy to share the Gospel, God can make stones talk (Luke 19:40). No matter what happens, it is 100% guaranteed that every single person whom God predestines will be saved. By contrast, those whom He does not predestine, He simply doesn't call. Or at least, He doesn't call them in a manner that would encourage them to repent. Many are called, and in fact the Bible says He commands all men everywhere to repent (Acts 17:30).
So, there is the Biblical understanding of Predestination. In the end, this is not an issue over which we should divide as much as we very often do. Jesus isn't sending us out there with a message of "God will save you if He wants, but if not, bad luck." No, God is sending us out to the human race with a message of faith and repentance: "Believe on the Lord Jesus and you will be saved" (Acts 16:31). Whatever your understanding of Predestination, let us not lose sight of that.