Does this mean we will completely understand all of Scripture? No, but the Holy Spirit will give us leading and understanding as we press in to know Christ.
Does this mean we will not have to wrestle with what we are reading and meditating on? No, but the Holy Spirit will give us the means to surrender our will to the Father's will.
The giver of Life uses His word to instruct us in His ways as opposed to our ways, to rebuke and correct us when our ways are contrary to His ways.
He will use His word to train us in the way of His righteousness by faith in Jesus Christ, replacing our feeble attempts to live righteous in our own strength outside of knowing Him.
2 Timothy 3:16 All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, 17 that the man of God may be complete, equipped for every good work. (2 Tim. 3:16 ESV)