The United States is not a Christian nation.
While there are many Christians living there they are by no means the only religion. and just because the money says "In God We Trust" does not make the US a Christian nation.
There are many religions that believe in God that are not Christian - the Jewish faith and Islam to name two major ones.
The First amendment of the US constitution states: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof ..." which is what Thomas Jefferson believed.
Which means there is no official religion of the US and it is wrong to label the US as a "Christian" nation.
It is a myth that the founding fathers of the US were Christians.
Many of them were Deists or Unitarians, including George Washington, the Adams brothers and Thomas Jefferson. In fact, Jefferson believed that eventually the Unitarian faith would be the dominate one in the US.
Obviously he was wrong, but he could not be labelled a Christian.
As to China being a peaceful nation, just look at what they are doing in the South China Sea. Granted that is far from the Cook Islands but what they are doing there looks far from peaceful.
China is threatening foreign ships and planes operating in the South China Sea on a "daily" basis, according to the chief of the armed forces of the Philippines.
The tone of the radio query directed at the US aircraft is noticeably softer than that of the call aimed at the Philippines plane.
Nonetheless, the US military had some strong words for China, which is rapidly expanding its military presence in the South China Sea through the deployment of jamming technology, anti-ship cruise missiles, surface-to-air missiles, and other defence equipment intended to tighten China's grip on the territories.
And it's not just planes. China also issues warnings to foreign ships, especially when the US Navy decides to conduct a freedom-of-navigation operation in the area.
None of this sounds very "peaceful" to me.