unswerving

1. ADJ If you describe someone's attitude, feeling, or way of behaving as unswerving, you mean that it is strong and firm and does not weaken or change. (態(tài)度、感受、行爲)強烈的; 堅定的[usu ADJ n]

...her unswerving belief in her father's innocence. ...她堅定地相信她父親是清白的。