'Useless' in the Bible

and not to pay attention to myths and endless genealogies, which cause useless speculations rather than God's plan [that is] by faith.

But avoid foolish controversies and genealogies and contentions and quarrels about the law, for they are useless and fruitless.

Once he [was] useless to you, but now [he is] useful to you and to me,

But do you want to know, O foolish person, that faith apart from works is useless?

For [if] these [things] are yours and are increasing, this does not make [you] useless or unproductive in the knowledge of our Lord Jesus Christ.