At the sanctuary/temple, only the high priest could approach the presence of God in the Holy of Holies on the Day of Atonement and with a protective smokescreen of incense, or he would die (Lev. 16:2, 12, 13). Isaiah saw the Lord, even though he was not the high priest, and he was not burning incense! The temple filled with smoke (Isa. 6:4), reminding us of the cloud in which God’s glory appeared on the Day of Atonement (Lev. 16:2). Awestruck and thinking he was finished (compare Exod. 33:20; Judg. 6:22, 23), Isaiah cried out with an acknowledgment of his sin and the sin of his people (Isa. 6:5), reminiscent of the high priest’s confession on the Day of Atonement (Lev. 16:21).
 “Standing, as it were, in the full light of the divine presence within the inner sanctuary, he realized that if left to his own imperfection and inefficiency, he would be utterly unable to accomplish the mission to which he had been called.” — Ellen G. White, Prophets and Kings, p. 308.
 Why did the seraph use a live, or burning, coal from the altar to cleanse Isaiah’s lips? Isa 6:6, 7.
 The seraph explained that through touching the prophet’s lips his guilt and sin were removed (Isa. 6:7). The sin is not specified, but it need not be limited to wrong speech, because lips signify not only speech but also the entire person who utters it. Having received moral purification, Isaiah was now able to offer pure praise to God.
 Fire is an agent of purification, because it burns away impurity (see Num. 31:23). But the seraph used a coal from the special, holy fire of the altar, which God Himself had lighted and which was kept perpetually burning there (Lev. 6:12). So, the seraph made Isaiah holy, as well as pure. There is more. In worship at the sanctuary, or temple, the main reason for taking a coal from the altar was to light incense. Compare Leviticus 16:12, 13, where the high priest is to take a censer full of coals from the altar and use it to light incense. But in Isaiah 6, the seraph applies the coal to Isaiah rather than to incense. Whereas Uzziah wanted to offer incense, Isaiah became like incense! Just as holy fire lights incense to fill God’s house with holy fragrance, it lights up the prophet to spread a holy message. It is no accident that in the next verses of Isaiah 6 (Isa. 6:8 and following) God sends Isaiah out to His people.
 Read prayerfully Isaiah’s response (Isa. 6:5) to his vision of God. How do we see in it an expression of the basic problem, that of a sinful people existing in a universe created by a “Holy, holy, holy” God? (Isa. 6:3, NRSV). Why was Christ on the cross the only possible answer to this problem? What happened at the Cross that solved this problem?