From the beginning of chapter 7 of Francis J Beckwith’s Return to Rome (Amazon link):
On May 5, 2007, I resigned as president of the Evangelical Theological Society (ETS) and two days later I resigned my membership, one I held for over twenty years. I did so because I quickly realized after my conversion had become public that there was no way that ETS could conduct business with my continued presence on the executive committee or in its membership. In fact, soon after my resignations, two members proposed extensive changes to the organization’s doctrinal statement [blogger addition: see ETS votes not to amend]. These changes, if passed would leave no doubt that ETS excludes all non-Protestants from membership. Thus, it seemed clear that if I did not resign my presidency and membership, my place in ETS would have been the focus of an intense debate within the society. Such a public and rancorous dispute over one individual would have needlessly ruptured many of my long-term friendships and alliances with members of ETS and the wider Evangelical world. And it may have also produced fissures in the growing collaboration and fellowship between Catholics and Protestants in the United States and abroad.
One may ask why I waited six days after my April 29, 2007 public reception into the Catholic Church to resign my ETS presidency and eight days to resign my membership. I did so because I did not believe that the ETS doctrinal statement was inconsistent with my Catholic beliefs. My resignations were motivated entirely by the reasons I stated in the previous paragraph. I did not want my return to the Catholic Church to cause needless offense to my brothers and sisters in Christ from whom I have learned so much in my over three decades in the Protestant world. Nevertheless, I still believe that the ETS doctrinal statement is broad enough to allow Catholic members. The purpose of this chapter is to explain why I believe this….
I hope this very readable but brief book gets expanded in the future.