Religion was "mumbo jumbo" to Gerhard
Gerhard himself, while technically a Jew, had little time for religion of any kind. In his words, he regarded it as superstitious mumbo jumbo.
To his way of thinking, all religious observance was hypocritically selective, be it the orthodox Jew splitting hairs to get around Sabbath restrictions; the circumvention by arcane means of Islam's prohibition on interest payments; or the Roman Catholic's unexacting forgiveness of misdemeanor following confession.
Gerhard was nevertheless always acepting and tolerant of others with their own differing views. He acquiesced without a murmur in Susie's upbringing as a Protestant. He attended without quibble her confirmation in the Church of England.
Likewise. he accepted his new family with pleasure. Gerhard had a high regard for Ilse's mother Adele, and he was similarly fond of young Uli. He always got on very well with Ilse's family. Had he the slightest doubts about them, he would have behaved entirely differently.
After the war, there were certain members of Ilse's family with whom Gerhard would not deal at all, and neither would Ilse, but these were rather distant relations.