As I pointed out when we discussed "elect," understanding about the trait "predestined" has gotten colored largely by the writings of the theologian, John Calvin. Again, I am not a follower of John Calvin. Nor perhaps even a good understander of ... But the term is used in the Bible.
Given my limited understanding of the original language, the word rendered "predestined" is a compund word: a word meaning "before" and a word from which the English word "horizon" is derived. And "horizon" has the inherent concept of "established boundaries" or "established limits." So, we are talking about pre-established boundaries.
Scripture says that before the beginning of time, God looked at each person to come. He chose to love those in Christ. He chose those in Christ to be holy. He chose to use the work of Jesus on the cross to bring us into his family.
● God's Perspective
It's one thing to say God chose before time those who would follow him, as some seem to say. It's another to say God chose before time how he would deal with those who chose to follow him.
It seems from my non-Calvinistic perspective, that what God determined beforehand was how he was going to treat those who gave him allegiance.
Even if he looked into the future at our lives, he would say, "That one is in Christ. I will love him, set him apart (or make holy) and bring him into my family." God decided before time to think about, act toward and relate with his children in a particular manner.
● Living My Life
I don't know about you, but I find I fail pretty consistently. I think wrong. I speak wrong. I do wrong. It is an encouragement to know that God has chosen how to interact with me, and because he does not lie, and always keeps his promises, he will always interact in the same way. Seeing my failures does not make me less his child. It does not affect any of the attention, time, energy or resources he has involved in restoring me to my original design, to Christ's image.
If the Father perseveres, then I can have hope, and I can persevere. And when I fall, I don't have to remain in the mud. It means something to get back on my feet, and to choose to move forward.