A firmly held belief or conviction; a principle or creed that one strongly adheres to.
彼女は最後まで自分の信念を曲げなかった。
She did not bend her convictions until the end.
教師としての信念が、彼を教育の道に留めた。
His convictions as a teacher kept him in the field of education.
どんなときでも自分の信念に従って行動することが大切だ。
It's important to act according to your convictions no matter what.