I wanted to compile a list of arguments drawn from the New Testament in support of the use of sacred imagery.
There are several passages in the New Testament that suggest that sacred imagery is okay to use in Christian churches. The most significant passages may be the ones about the Temple. The Jewish Temple, located in Jerusalem, was the primary place of worship for the Jews, and the early Christians used the Temple for worship before separate Christian churches were built.  But the Temple was decorated with sacred imagery.  This suggests that the early Christians had no problem worshiping in a building decorated with sacred imagery.
A second piece of evidence for Christian imagery in the New Testament is also related to the Temple. The Book of Hebrews significantly mentions the Temple, its decorations, and its images in a passage that sounds like a defense of the right of Christians to make physical churches: “Now even the first covenant had regulations for worship and an earthly sanctuary. For a tent was prepared, the outer one, in which were the lampstand and the table and the bread of the Presence; it is called the Holy Place. Behind the second curtain stood a tent called the Holy of Holies, having the golden altar of incense and the ark of the covenant covered on all sides with gold, which contained a golden urn holding the manna, and Aaron’s rod that budded, and the tables of the covenant; above it were the cherubim of glory overshadowing the mercy seat. Of these things we cannot now speak in detail.” Hebrews 9:1-5. By saying “Even the first covenant had…an earthly sanctuary,” with images of cherubim decorating it, it sounds like he is defending the right of Christians to have similar buildings.
A third piece of evidence for Christian imagery in the New Testament is in John 3:14-15. There, Jesus brings up the story of a bronze statue that Moses made at the command of God, and Jesus says it was a figure of His crucifixion. This suggests that there can be statues of made of Jesus’ crucifixion. Also, St. Paul possibly mentions an early crucifix in Galatians 3:1. Even if it wasn’t a crucifix, St. Paul still at the very least compares it to something graphical twice: “It was before your eyes that Jesus Christ was publicly portrayed as crucified.” Galatians 3:1. In this passage, St. Paul at the very least compares the vividness of the crucifixion to an image in a positive way. This count as a fourth piece of New Testament support for Christian imagery.
A fifth piece of evidence is this: several of the passages of the Bible are described in vivid detail that paints a mental picture in the minds of listeners. It is only a natural development of this that these vivid descriptions would be painted. Thus, Christian imagery goes back to the New Testament and developed from that source.
Footnote 1: The second link in the second paragraph of this post shows that the Jewish Temple was decorated with sacred imagery. After the Babylonians destroyed it, a second temple was built which lasted until shortly after the time of Christ. According to the Jewish historian Josephus, it too was decorated with sacred imagery: “[the] gate…[was] all over covered with gold, as was its whole wall about it; it had also golden vines above it, from which clusters of grapes hung as tall as a man’s height. … [A] curtain had also embroidered upon it all that was mystical in the heavens, excepting that of the [Zodiac] signs.” (Wars of the Jews Book V Chapter V Paragraph 4)
Footnote 2: The Apostles worshiped in the Temple in Luke 24:52-53, Acts 2:46, Acts 3:1-3, 8, Acts 5:21, 42, Acts 21:26, Acts 22:17, Acts 24:18, and Acts 26:21. Jesus worshiped in the Temple in Matthew 21:12-13, 23, Mark 11:11, 15-17, 27, 12:35, Luke 2:46-49, Luke 19:45-47, Luke 20:1, Luke 21:37-38, John 2:14-17, John 5:14, John 7:14, 28, John 8:2, 20, John 10:23, and John 18:20.
So there you go. Five layers of support for Christian imagery in the New Testament. BTW I’d love to add to this; do you know of any other New Testament passages that can be used to support the use of Christian imagery?