The last enemy that will be abolished is death.

Then [i.e., at Christ's return] the end [of the world] will occur, when He will turn over the kingdom to God, the Father, after He has abolished all [hostile] dominion, authority and power. For Christ must [continue to] rule [over His kingdom, the church] until God has put all of His enemies under Christ's feet. The last enemy that will be abolished is death.read more.
For He [i.e., God] placed everything in subjection under His [i.e., Christ's] feet. But when God said, "Everything is in subjection [to Him]," it is clear that this did not include God [Himself], who placed everything in subjection to Him [i.e., Christ]. And after everything [else] has been subjected to Christ, then the Son Himself will also be subjected [i.e., He will subject Himself] to God, who subjected everything to Christ, so that God may rule over everything.

Now David is not the one who ascended into heaven for he [spoke of Jesus when he] said [Psa. 110:1], 'The Lord [i.e., God] said to my [i.e., David's] Lord [i.e., Jesus], sit at my right side until I put your enemies [in subjection] beneath your feet.'

But which one of the angels did God ever say [this] about [Psa. 110:1], "You should sit at my right side until I put your enemies [in full subjection] beneath your feet"?