" We cannot look into the Book of Life and see whether our names are amongst those of whom the Lord says, "thine they were, and thou gavest them me"; but we can look into the Word of God..."
Marcus Rainsford - Our Lord Prays For His Own
What a great way to look at Scripture. We can read it and know with assurance how our salvation is achieved, yet there is much we cannot understand now. And that makes no difference, because we can know what we need to know from it. In our pride we want to be able to understand all there is to Scripture, and many will dismiss those portions that clearly require a sovereign God because our finite existence and minds cannot comprehend. When you reflect on Scripture, that should not be a surprise:
Now faith is the assurance of things hoped for, the conviction of things not seen. Hebrews 11:1 (NASB)
So, you may not understand without difficulty, but you can so believe.