'Sincerity' in the Bible

"So then, if you have acted in good faith and sincerity in making Abimelech king, and if you have dealt well with Jerub-Baal and his house, and have dealt with him {according to his accomplishments}--

if you have acted in good faith and sincerity with Jerub-Baal and his house this day, then rejoice in Abimelech, and let him also rejoice in you.