Isaiah 1:29 "For you shall be ashamed of the oaks in which you delighted; and you shall blush for the gardens which you have chosen."

This is part of God's "opening statement" to Isaiah, in which He tells Isaiah His people are corrupt and He is getting ready to "turn [His] hand against [them] and smelt away [their] dross as with lye and remove all [their] alloy." (Isaiah 1:25) God says "Zion will be redeemed by justice, and those in her who repent, by righteousness." (Isaiah 1:27)

In our free will and His mercy, God lets us go away from Him, often very far, hoping that we will turn back as we experience the lesser effects of our separation from Him. But eventually the only thing we will respond to is His justice, which itself has a tremendous redemptive effect. Many have to be punished before they repent ("redeemed by justice", as God says), especially when the society they are living in is so far gone that even their leaders are corrupt and leading them astray.

These leaders are the "oaks" God speaks of in this verse. They are the people society looks up to as strong, stable, moral examples. They have a great responsibility to guide us rightly by their words and deeds. When society has gone too far down the path of unrighteousness, however, these leaders can be corrupt or deceived themselves, and can preach unholy nonsense that further leads the people astray. When the truth is revealed, or when people finally wake up and see it for themselves, these "mighty oaks" look more like propped up twigs. We become very ashamed of ourselves for listening to them, following their example, and repeating their misguided "wisdom." That is how God promises Zion will feel about her leaders, and that is how we should feel about many of ours.

God also says his people will "blush for the gardens which they have chosen." (Note that He doesn't say the gardens we've grown, but the gardens we've chosen, a reference to our choosing not to remain in the Garden of Eden). This is similar to our looking up to the wrong leaders. When society goes so far astray that good is called evil and evil good, we cannot see properly, and we look on the most ugly things as beautiful. These are the gardens we have chosen. When we wake up, or when the truth is revealed, we find our "beautiful garden" to be a pile of mud and weeds that we have convinced ourselves was beautiful. We feel so ashamed for so deceiving ourselves or allowing ourselves to be deceived.

There were people who saw the flimsiness of our oaks and the ugliness of our gardens long before I did, and I am so grateful for them. Many of them are saints whose timeless wisdom pricks at our blindness until we open our eyes. Once we see it, there is no going back. The only garden we desire is that of God, and the oaks we look up to are His humble servants and saints who tell us how to choose that garden by telling us the truth in this world of lies.