Question: If the bible teaches that everything, especially one's salvation, is predestined, then why do we even need to go through the motions, like "accepting" Christ?
Answer: Thank you for submitting such a substantive question! Since you did not reference any specific verses, I'll include a small sampling that reference God's predestination. That way we can be sure that we're talking about the same thing.
“Who can bring a clean thing out of an unclean? There is not one. Since his days are determined, and the number of his months is with you, and you have appointed his limits that he cannot pass,” (Job 14:4–5, ESV)
“even as he chose us in him before the foundation of the world, that we should be holy and blameless before him. In love” (Ephesians 1:4, ESV)
“he predestined us for adoption as sons through Jesus Christ, according to the purpose of his will,”
(Ephesians 1:5, ESV)
“For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers. And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified...Who shall bring any charge against God’s elect? It is God who justifies.” (Romans 8:29–33, ESV)
Predestination is one of the most difficult biblical topics to parse because, on the surface at least, it seems to challenge the core of evangelical thought. We Evangelicals must be…well…evangelical to be congruent, meaning that we must preach the Gospel, declare Christ crucified, plead with men to come to the cross and be saved, and all that seems to be an empty exercise when viewed through the prism of Calvinistic predestination. That's the type of predestination your question presupposes, where God has predetermined who will be saved and who will be lost. So, your question is well taken. Why indeed would anyone have to accept Christ when, at the end of the day, God will somehow sweep them up into salvation in spite of themselves? In this we have our central conundrum, because there is a huge body of Scripture that teaches that we must be proactive in advancing the Gospel of Jesus Christ, and, with both in view, it seems as if the two systems are in tension.
Before we proceed, let me be clear that Scripture does indeed teach predestination—big, fat—and (nearly) Calvinistic! But my first observation is this: What does that affect in real-time? Please note that I'm not asking you to describe your stand on a theological issue, but rather, how do you think that predestination affects us where we live? I ask, because I think that it affects us very little if at all. And if that is true, then it would be a spiritual crime to just sit back and watch God be sovereign.
As a practical matter, any of the fatalistic trappings that would likely be generated by subscribing to a strict view of predestination are mollified by the many scriptures that command us to behave in ways that necessarily ignore it. In this we see that predestination is primarily informational. It give us important insights into God's sovereignty. But it is not at all practicable. Let's examine it for a moment. Predestination is mysterious, wonderful, horrible—a great doctrine to ponder…but it has no feet! Predestination is God's business, and not ours.
Nowhere in Scripture do we find predestination served-up as a behavioral objective for God's people, and this is (in my opinion) the most useful insight to make sense of that doctrine here on earth. Predestination and election are performed by a sovereign God—and not by us! So, no matter where you stand on these doctrines, there is nothing that you or anyone else can do about them. Plus, we know that predestination is not the end of the salvation story. If it were, then why does the Holy Spirit continue to woo the sinner? (John 16:8, 11). Why does the Father continue to draw them? (John 6:44). Why are believers instructed to preach, teach and baptize? (Matt. 28:19). For the practicable application of faith, it is critical to note that predestination has no feet. The Gospel, however, has plenty...and we'd better keep using ours to spread the good news of Jesus Christ.
I feel that it's important to look at the person of the Apostle Paul at this time. After all, he is the one who penned many of the important verses about predestination. Since he is responsible for a lot of the buzz, his personal response to the doctrine should be weighed with great care.
“For you have heard of my former life in Judaism, how I persecuted the church of God violently and tried to destroy it. And I was advancing in Judaism beyond many of my own age among my people, so extremely zealous was I for the traditions of my fathers. But when he who had set me apart before I was born, and who called me by his grace, was pleased to reveal his Son to me, in order that I might preach him among the Gentiles, I did not immediately consult with anyone;” (Galatians 1:13–16, ESV)
The Holy Spirit guided Paul to write (and in the same breath, by the way) that predestination and evangelism are not mutually exclusive. Paul avers that he was set aside by God before he was born—and that's quite predestinative! But for what purpose? To preach him among the Gentiles—and that's pretty evangelical! Apparently, neither God nor the Apostle Paul feels the tension between predestination and evangelism, so why should we?
Furthermore, can we know the mind of God beyond his revelation to us? No. Will we plumb the depths of his predestination and election? Hardly. But the fact that God has revealed certain structures that are beyond our ken should never dull our enthusiasm for performing his clearly stated instructions, nor should they give us mental anguish as if those two enterprises were indeed mutually exclusive. Do you want to know what to do about predestination? Do what the Apostle Paul did in his encounter with the Philippian jailer.
"And the jailer called for lights and rushed in, and trembling with fear he fell down before Paul and Silas. Then he brought them out and said, 'Sirs, what must I do to be saved?' And they said, 'Believe in the Lord Jesus, and you will be saved, you and your household'...” (Acts 16:29–32, ESV)
How did Paul answer the question, What must I do to be saved? Did he give the jailer a lecture on God's predestinative ways or on his electional proclivities? No. Did he qualify to the jailer that, if he were among those who were mysteriously chosen before the foundations of the earth that he would be saved...but otherwise he would be lost? No! He went right for the active heart of the Gospel: Believe in the Lord Jesus Christ, and you will be saved!
At this point I must ask, do you think that the Apostle Paul understood what he was writing when he wrote about predestination? I think so, too. But that didn't stop him from leading that jailer to Christ, and one need not look too far to find other examples of the disciples preaching, teaching and witnessing—but not about election! About the Lord Jesus Christ and him crucified. And that is what the Bible teaches about predestination and election. Don't let their theological heft bog you down. We have clear commands to preach, teach, baptize and make disciples. Never allow arguable theology to stop your movement toward God's clearly stated objectives.
This concludes my response to the practical side of the issue. I'm not the man to resolve the theological side for you, though. Great men line up in both camps. They are often brothers, and this puts us at a dangerous place. Either I am wrong, Calvin is wrong, or the Bible is wrong...and I don't like that last one. Fortunately, there is another option. The Bible is correct—but the rest of us just don't fully understand how everything in it relates to everything else in it at this time. I like that option and here's why. Any God worth having should be a God whose thoughts and ways are far beyond those of his creatures.
“For my thoughts are not your thoughts, neither are your ways my ways, declares the Lord.”
(Isaiah 55:8, ESV).
That is not to say that God does not engage and teach his creatures appropriately—for he surely does that! But what good is it if an infinite God does not stretch us to where we find the ends of ourselves? He does that with salvation. No one is saved who was not found the end of himself in sin. Why would our walk with Christ be any different? We routinely have to find the ends of ourselves to rely on the Holy Spirit to do God's will. So, should we be so arrogant as to assume that we mortals will fully fathom God's scriptures while we're here on earth, and that nothing will be left for us on that day? By way of testimony, it is here, where predestination and the Gospel meet, that I find the end of myself...and from what I've read, so has everyone else.
I pray that this all helped more than it has confused. Either way, God is faithful. God is good.