G3152–μάταιος–mataios

"Men, why are you doing these things? We also are men of like passions with you, and bring you good news, that you should turn from these vain things to the living God, who made the sky and the earth and the sea, and all that is in them;

ματαίων mataiōn “vanities”

And again, "The Lord knows the reasoning of the wise, that it is worthless."

μάταιοι. mataioi “futile.”

If Christ has not been raised, your faith is vain; you are still in your sins.

ματαία mataia “[is] futile”

but shun foolish questionings, genealogies, strife, and disputes about the law; for they are unprofitable and vain.

μάταιοι. mataioi “worthless.”

If anyone among you thinks himself to be religious while he doesn't bridle his tongue, but deceives his heart, this man's religion is worthless.

μάταιος mataios “worthless [is]”

knowing that you were redeemed, not with corruptible things, with silver or gold, from the useless way of life handed down from your fathers,

ματαίας mataias “futile”