Jesus came to execute God's will as revealed in His law and the prophets not to abolish what God had already established as the moral basis for human conduct, stability, freedom and prosperity. Jesus, being the son of God could not destroy the moral law of God and neither should we. As hard as the law of God may seem to us we are to obey it.
Benjamin Franklin Morris' book has been out of print for more than 100 years. If you can find an original copy, it's only because you have looked in the deep recesses of university libraries where the volume is probably collecting dust on dimly lit library shelves. Organizations like the ACLU and Americans United for Separation of Church and State have done their best to ignore the content of the massive compilation of original source material found in this book. If Americans ever become aware of the content assembled by the author, the arguments for a secular founding of America will turn to dust.