What do those quotes have to do with Christianity? Not being critical, just curious?
Did you actually read them? The text in red shows that when they mention God and religion, they are referring to the God of the Bible and Christianity.
Thomas JeffersonNotes on Virginia, 1782:God who gave us life gave us liberty. And can the liberties of a nation be thought secure when we have removed their
only firm basis, a conviction in the minds of the people that these liberties are of the Gift of God? That they are not to be violated but with His wrath? Indeed, I tremble for my country when I reflect that God is just; that His justice cannot sleep forever.
John AdamsLetter to Thomas Jefferson, 1812"The Ten Commandments and
the Sermon on the Mount contain my religion."
Letter to Zabdiel Adams, 21 June 1776:Statesmen, my dear Sir, may plan and speculate for liberty,
but it is Religion and Morality alone, which can establish the Principles upon which Freedom can securely stand. The only foundation of a free Constitution is pure Virtue, and if this cannot be inspired into our People in a greater Measure, than they have it now, they may change their Rulers and the forms of Government, but they will not obtain a lasting liberty.
Letter to Abigail Adams, 3 July 1776:The second day of July, 1776, will be the most memorable epocha in the history of America. I am apt to believe that it will be celebrated by succeeding generations as the great anniversary festival. It ought to be commemorated as the day of deliverance,
by solemn acts of devotion to God Almighty. It ought to be solemnized with pomp and parade, with shows, games, sports, guns, bells, bonfires, and illuminations, from one end of this continent to the other, from this time forward for evermore.
Diary, 26 July 1796:The Christian religion is, above all the religions that ever prevailed or existed in ancient or modern times, the religion of wisdom, virtue, equity, and humanity.
Address to the Military, 11 October 1798:We have no government armed with power capable of contending with human passions unbridled by morality and religion. Avarice, ambition, revenge, or gallantry, would break the strongest cords of our Constitution as a whale goes through a net.
Our Constitution was made only for a moral and religious people. It is wholly inadequate for the government of any other.