“Jesus Christ the same, yesterday and today, and forever.” (Hebrews 13:8) By “yesterday” the writer of Hebrews refers to the three-and-a-half years of ministry of Jesus on earth; and by “today” he refers to the time when the glorified LORD Jesus in heaven continues to do through his followers on earth what he had done here during his own ministry.
The conjunctive “and” is used twice in this verse to not only connect “yesterday” with “today” but also “today” with “forever”. So “forever” cannot be limited to the timeline of the Book of Acts, or the lifetimes of the first apostles, which can hardly be described as “forever” — through and beyond Time into endless eternity.
No, it is only logical to define “forever” (perpetuity in NT Greek: “the ages of the ages”) as including the time of the writing of the Book of Hebrews in the first century, and as extending beyond Time into Eternity.
We know from the Gospels what Jesus did “yesterday” during his earthly ministry, and we know from the Book of Acts what he did after his resurrection through his apostles. However, we also know what the Lord continued to do after Chapter 28 of the Book of Acts down through church history until the present day.
Little-known or unrecorded successive chapters of the acts of Jesus through God’s miracle-working power through those who believe continued for 2,000 years and do so today — and will until the Lord Jesus returns. To believe otherwise is to deny the clear statement of Hebrews 13:8.
No, miracles of healing have not ceased; what has is the diminished faith of those who deny them.