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. (态度、感受、行为)强烈的; 坚定的[usu ADJ n]

...her unswerving belief in her father's innocence. ...她坚定地相信她父亲是清白的。