deathbed conversion

noun2

1. •
   Acceptance of religious belief immediately before one dies, typically in a state of anxiety or fear of the insecurity of what will happen to one in and after death.

   • Mr. Hitchens discussed the possibility of a deathbed conversion, insisting that the odds were slim that he would admit the existence of God. — 2011
2. •
   An abrupt, last-minute change in one's professed beliefs, principles, or point of view in order to escape a serious threat or to increase one's chances of success.

   • The dilemma was how to propose a big tax cut and still look credible. Dole knew that the Democrats would mock him for a deathbed conversion. — 1996