The design of the flag came from General Washington’s secretary, Colonel Joseph Reed. In a letter dated October 21, 1775, Reed suggested a “flag with a white ground and a tree in the middle, the motto AN APPEAL TO HEAVEN” be used for the ships Washington commissioned.[2]
The following summer, on July 26, 1776, the Massachusetts General Court established the flag of the state navy with a resolution that stated in part: “...that the Colours be a white Flag, with a green Pine Tree, and an Inscription, ‘Appeal to Heaven’.”
https://en.wikipedia.org/wiki/Pine_Tree_Flag
Galatians 4:6 And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father.