Hebrews 7:8 indicates that Melchizedek lives. Here mortal men receive tithes, but there he receives them, of whom it is witnessed that he lives (Hebrews 7:8 NKJV) but he whose genealogy is not derived from them received tithes from Abraham and blessed him who had the promises (Hebrews 7:6 NKJV)
Hebrews 7:3
ESV - 3 He is without father or mother or genealogy, having neither beginning of days nor end of life, but resembling the Son of God he continues a priest forever.
For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
There are 2 examples in the Old Testament of human beings who did not suffer physical death.
Enoch in Genesis 5:24.
Elijah in 2 Kings 2:11
There are 3 examples in the New Testament of human beings who died but we know they are spiritually alive.
In Jesus parable if the Rich Man and Lazarus, the patriarch Abraham has a conversation with the rich man.
In the event of Jesus Transfiguration on the Mountain, the 3 disciples see and hear Jesus talking with Moses and Elijah.