We are not allowed to claim promises specific to someone else as if they arte for us.
First, notice who is being addressed. God is speaking directly to Solomon, though Israel as a nation is clearly in view. In fact, God is giving Solomon a point-by-point response regarding his prayer for Israel in 2 Chronicles 6. Therefore, the promise of blessing and the warning regarding disobedience was given to Israel, not America or Christians living in America.
Second, what is “this place” that God has chosen in verse 12? Clearly it refers to the temple Solomon built in Jerusalem, not America.
Third, who is the group of “my people” that God is referring to in verse 14? It is certainly not Christians under the new covenant. That is an anachronistic reading which would be completely foreign to the original author and audience. Clearly this is referring to the Israelite nation. The nation of Israel was God’s chosen people in the Old Testament, not America or Christians living in America.
Fourth, what “land” is God promising to heal in verse 14? Again, clearly this is referring to the promised land of Israel, not America.
Fifth, what exactly is meant by “heal their land” in verse 14? Many assume this refers to some sort of spiritual healing, a spiritual revival of sorts. This is the way it is often applied today. But notice what verse 13 states, a verse that is frequently skipped over to get to verse 14:
http://apologeticjunkie.blogspot.com/2010/03/text-out-of-context-2-chronicles-714.html
Let's just say, I am God's people because I have been "adopted" in or grafted into the Root. The Jews are my family now.
Second, the Temple today is my body and God lives in me. He has sanctified this house and will hear the prayers made in "this house".
The Old Testament is the physical reality of history that told the story of things to come. The New Testament changed NOTHING, except the fulfillment of the promises made in the OT. Remember Jesus said He didn't come to change the Law, but to fulfill it. The Grace of Jesus was that He agreed to pay our sin price, but the price still had to be paid. If Psalms speaks of Christ on the cross through David, then Genesis speaks of things to come that are today, reality. In the NT, Sodom and Gomorrah are mentioned and the "time of Noah, and many other references are made to the OT.
Verse 19-22 speaks of the house(my body or temple), and the land given to them.
The Bible speaks of God's character. What was true then is true today because He is unchanging. America is just a chunk of land, but it was given by God to us. The Bible doesn't have to call it by name. If you lived in Mexico and they had revival, would they not be blessed? As we turn from God, we all suffer. That is an ageless principle.