In his final sermon before he was martyred, Stephen recited the history of rebellious Israel. Referring to the idolatry of the ancient Israelites, Stephen mentioned the god Molech and “the star of your god Rephan” (Acts 7:43). Other versions of the Bible spell the name of the false god as Remphan (KJV, NKJV) or Rompha (NASB, AMP). They are all talking about the same false god.
In the context of Stephen’s reference to “the star of your god Rephan,” he mentions the golden calf that Israel worshiped at Sinai (Acts 7:39–41). He then says that “God turned away from them and gave them over to the worship of the sun, moon and stars” (verse 42). One of those “stars” they worshiped was the star of Rephan (verse 43). Finally, Stephen points to God’s determination to send Israel into exile in Babylon (verse 43). Stephen’s argument before the Sanhedrin was that the current generation of Israel was just as “stiff-necked” as their ancestors, “always resist[ing] the Holy Spirit!” (verse 51). They had proved their stubbornness in their rejection of Jesus Christ.
When he referred to the “star of your god Rephan,” Stephen was quoting the Greek translation of the Old Testament Scriptures known as the Septuagint, or LXX. This translation by Hebrew scholars was completed about the third century BC. The passage Stephan quotes is Amos 5:26, which in an English translation of the LXX reads, “Yea, ye took up the tabernacle of Moloch, and the star of your god Raephan, the images of them which ye made for yourselves” (tr. by Sir Lancelot Brenton, 1851).
In the Hebrew text of Amos 5:26, the name the LXX translates as “Raephan” is Kiyun, spelled Chiun (KJV), Kaiwan (NLT, CSB), or Kiyyun (ESV), depending on the Bible version. Some versions, such as the NIV, do not transliterate the word at all.
The International Standard Bible Encyclopedia identifies Rephan as “the Babylonian name for the god of the planet Saturn.” The International Standard Bible translates Amos 5:26 as “And you carried the tent of your king—and Saturn, your star god idols that you crafted for yourselves.” Smith’s Bible Dictionary and Easton’s Bible Dictionary also link Rephan (or Remphan) to the god Saturn.
It seems the Babylonians worshiped a god of their own imagination and named him “Kiyun,” whose place in the heavens was as a “wandering star” that they also named “Kiyun” after their god. All the ancient peoples had observed that some stars—in actuality planets—moved through the sky, while other stars—the genuine stars—were fixed. (The Greek term asteres planētai, shortened to just planētai, meant “wandering stars.”) The ancients made no distinction between stars and planets; to them, they were all stars of some type. Thus, Saturn was considered a “star,” and the deity associated with him was a “star-god.”
The god Kiyun was worshiped among the ancient Babylonians, Arabs, Syrians, and Assyrians. Every false god had its representation, its idol. Molech was represented by a brass bull; Astarte by a tree; Dagon by a half-man, half-fish; and Kiyun by a star—the wandering “star” we know as the planet Saturn.
In short, “the star of your god Rephan” mentioned in Acts 7:43 is a pagan god that some ancient Israelites unwisely worshiped in the wilderness. The name Rephan is an English translation of the LXX translation of the Hebrew word Kiyun.
Contrary to some theories, the star of Rephan has nothing to do with the six-pointed Star of David featured on the Jewish flag. Also, there exists no genuine star in the heavens that has any historical or religious relationship with Saturn/Kiyun.