For the Lord of hosts has a day against all that is proud and lofty, against all that is lifted up and high; against all the cedars of Lebanon, lofty and lifted up; and against all the oaks of Bashan; against all the high mountains, and against all the lofty hills; against every high tower, and against every fortified wall; against all the ships of Tarshish, and against all the beautiful craft. And the haughtiness of man shall be humbled, and the pride of men shall be brought low; and the Lord alone will be exalted in that day. — Isaiah 2:12-17
There are two ways to translate Isaiah 2:12, and both are accurate because both are represented in the Greek and the Hebrew. The first can be seen in the translation above where the Lord is against all that is lifted up. The second is the idea that the Lord is above/over/upon all that is lifted up. In other words, we have all these things that we put value on, and raise up to a point where we covet these more than we want to be with God. Isaiah give us a list of these things that his contemporaries highly valued: the cedars of Lebanon, the oaks of Bashan, high mountains and hills (holy places for pagans), towers and walls (to protect cities and all the valuable stuff therein) and the ships of Tarshish and other beautiful craft.
God is over and above all these things because He created them from nothing. They only exist because He wills it. God is against these things, because we have made them into things that separate us from Him. They manifest and are a source of sin.
One of the things we must learn as Christians is to read the OT through the lens of Jesus Christ. On the road to Emmaus, the resurrected Lord instructs Luke and Cleopas:
beginning with Moses and all the prophets, he interpreted to them the things about himself in all the scriptures. — Luke 24:27
The OT tells us about Christ, so we need to read the OT from the perspective of Christ incarnated, crucified and resurrected.
When Isaiah tells us that the Lord of hosts has a day against all these things that lead us to sin, we are allowed to understand that day as the day of the resurrection. God never wanted for His creation to be apart from Him or used to separate us from Him. So, He became one of us in the person of Jesus Christ. He waged war against all that separates us from Him by going to the Cross. He rose from the dead and with our humanity ascended to sit at the right hand of the Father in glory. In Christ we have the means by which to overcome all that separates us from God.