The Bible says he was chosen by to replace Judas as one of the Twelve Apostles. If your view is in conflict with what Scripture says, then wouldn't it make sense that you should re-evaluate your position, rather than call Scripture into question?
I think it's important to point out that within historic Protestantism there are two schools of thought on predestination: Reformed and Lutheran. I'm a Lutheran, and your objection to predestination sounds more like an objection to the Reformed/Calvinist view of predestination.
Predestination doesn't mean "God chose you, and so you can't help but be saved", it just means that God chose you, in Christ.
For the Lutheran perspective on this topic, there's not really a better resource than the Lutheran Confessions themselves, in particular the Solid Declaration of the Formula of Concord and the Epitome of the Formula of Concord, which specifically addresses the Lutheran understanding of Predestination and Election.
The Solid Declaration on Election:
Here.
The Epitome on Election:
Here.
Yes, you were predestined in Christ, by the grace of God. You can turn away, reject it, fall away and shipwreck your faith. But you can't change God's love and mercy which He has for you. Christ is, as Luther put it, the bloodhound of heaven, or as our Lord Himself says, the Good Shepherd. He is relentless in His love. This is good news, to you, a sinner. Take comfort in God's relentless pursuit of you.
-CryptoLutheran