Taking 'I am sure you will understand my writing to you once more about the important work of the American Cancer Society.' as a given, does it logically imply 'I hope that I can convey the importance of the American Cancer Society but writing to you again.'
I am sure you will understand my writing to you once more about the important work of the American Cancer Society.###I hope that I can convey the importance of the American Cancer Society but writing to you again.