Power's not what the Constitution was about.
America promotes a lot of bad things, you know. Same-sex marriage, for example.
Without God there would be no freedom to believe what you want.
It can have a secular purpose and have a relationship to God because God was presumed to be both over the state and the church, and separation of church and state was never meant to separate God from government.
Separation of church and state was never meant to separate God and government.
Indeed, the acknowledgement of God is not synonymous with religion.