5 and have tasted the good word of God and the powers of the age to come,
5 and have tasted the good word of God
“Tasted” here relates to both the Word of God and “the powers” (miracles). These two ideas are connected by the word “and” in the next phrase. “Tasted” again means to experience the Word of God. The idea is not that they sampled Christianity but that they experienced it fully. These people had received genuine teaching from the New Testament. They knew how “good” it was; they fully embraced its message.
and the powers [miracles] of the age to come,
These Christians saw something of the miracle of Jesus’ resurrection, among other miracles (He 2:4). The “age to come” is the New Testament age.
This passage does not refer to merely professing Christians.
Verses 5 and 6 cannot refer to professing Christians who were not truly born again. The language of this verse clearly speaks of those genuinely born again. One would have to force the meaning of simply professing believers upon this passage.