G3152–μάταιος–mataios

We also are but men, with natures kindred to your own; and we bring you the Good News that you are to turn from these unreal things, to worship the ever-living God, the Creator of earth and sky and sea and of everything that is in them.

ματαίων mataiōn “vanities”

And again, "The Lord takes knowledge of the reasonings of the wise--how useless they are."

μάταιοι. mataioi “futile.”

and if Christ has not risen, your faith is a vain thing--you are still in your sins.

ματαία mataia “[is] futile”

But hold yourself aloof from foolish controversies and pedigrees and discussions and wrangling about the Law, for they are useless and vain.

μάταιοι. mataioi “worthless.”

If a man thinks that he is scrupulously religious, although he is not curbing his tongue but is deceiving himself, his religious service is worthless.

μάταιος mataios “worthless [is]”

knowing, as you do, that it was not with a ransom of perishable wealth, such as silver or gold, that you were set free from your frivolous habits of life which had been handed down to you from your forefathers,

ματαίας mataias “futile”