It is certainly true that God’s ultimate end and purpose can never change. His never-changing end is that all His human children may know Him, as Christ knows Him. His unalterable purpose is that all of us, every single one, be conformed to the image of Christ, that we become full and mature members of the Divine Family.
That never changes. We all have the same ultimate destination. But the way there is not fixed. The changes of the season may be fixed by the motions of the earth in relation to the sun; the fall of avalanches may be determined by the mass and weight of the snow and the angle of the mountainside; the explosion inside the piston may be necessitated by the spark and the mixture of compressed gasses inside. But the journey of each individual soul towards God is neither fixed, nor determined, nor necessitated. That’s because we are God’s children, created in God’s image. That freedom and the responsibility that attaches to it are what separates us from the inanimate parts of God’s creation.
And that same difference, that same freedom, is why Jesus teaches us to pray. To imagine a God who is so bound by the mechanical laws of His own creation that He could not intervene to alter the course of that creation is to imagine a God who has less freedom than we do ourselves.
To imagine a God who would create children with a sense of their own freedom, and who exercise that freedom by turning to their Father in submission and appealing to Him for help, but who would willfully and eternally ignore those pleas for assistance, is to imagine a God, not of infinite love, but of infinite cruelty.