Seraphim appear twice in the King James Version
Isaiah 6:1 In the year that king Uzziah died I saw also the Lord sitting upon a throne, high and lifted up, and his train filled the temple. 2 Above it stood the seraphims: each one had six wings; with twain he covered his face, and with twain he covered his feet, and with twain he did fly. 3 And one cried unto another, and said, Holy, holy, holy, is the LORD of hosts: the whole earth is full of his glory. 4 And the posts of the door moved at the voice of him that cried, and the house was filled with smoke. 5 Then said I, Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips: for mine eyes have seen the King, the LORD of hosts. 6 Then flew one of the seraphims unto me, having a live coal in his hand, which he had taken with the tongs from off the altar: 7 And he laid it upon my mouth, and said, Lo, this hath touched thy lips; and thine iniquity is taken away, and thy sin purged. 8 Also I heard the voice of the Lord, saying, Whom shall I send, and who will go for us? Then said I, Here am I; send me.
The Hebrew word translated ‘seraphims’ is ‘saraph’ which is elsewhere translated ‘fiery’ and ‘serpent’.
Numbers 21:6 And the LORD sent fiery serpents among the people, and they bit the people; and much people of Israel died.
Numbers 21:8 And the LORD said unto Moses, Make thee a fiery serpent , and set it upon a pole: and it shall come to pass, that every one that is bitten, when he looketh upon it, shall live.
Isaiah’s vision is one of symbols. The seraphim are not literal beings. Like the cherubim, they are symbolic rather than real creatures. The description of the four beasts in Revelation is similar to the seraphim and they give glory to God with the similar words ‘Holy, holy, holy, Lord God Almighty...’
Revelation 4:6 And before the throne there was a sea of glass like unto crystal: and in the midst of the throne, and round about the throne, were four beasts full of eyes before and behind. 7 And the first beast was like a lion, and the second beast like a calf, and the third beast had a face as a man, and the fourth beast was like a flying eagle. 8 And the four beasts had each of them six wings about him; and they were full of eyes within: and they rest not day and night, saying, Holy, holy, holy, Lord God Almighty, which was, and is, and is to come. 9 And when those beasts give glory and honour and thanks to him that sat on the throne, who liveth for ever and ever,
We are told that Isaiah was seeing a vision of the future glory of Christ, the time when he will reign in glory with his saints.
John 12:41 These things said Esaias, when he saw his glory, and spake of him.
There is a connection with Christ and the fiery serpent that Moses made:
John 3:14 And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up: 15 That whosoever believeth in him should not perish, but have eternal life.
John 12:32 And I, if I be lifted up from the earth, will draw all men unto me.
No other information on the Seraphim is given in the Bible.
The four faces are almost certainly the four standards of the camp of Israel. They also represent the four characteristics of the perfect man of God. Lion – king / courage; calf or ox – servant; man – compassion/priest; flying eagle – spiritual sight.
The four gospels would seem to represent these characteristics of Christ.
Matthew – king; Mark – servant; Luke – man; John – eagle.
All who serve God aspire to the characteristics of Christ.
The seraphim, like the cherubim, represent men and women who serve God and their details therefore have spiritual significance.
The seraphim have six wings. Six is generally understood to represent man (being the created on the sixth day).
With two they cover their face representing humility.
Isaiah 66:2... but to this man will I look, even to him that is poor and of a contrite spirit, and trembleth at my word.
With two they cover their feet representing taking care how they walk.
John 13:10 Jesus saith to him, He that is washed needeth not save to wash his feet, but is clean every whit: and ye are clean, but not all.
With two they fly representing swift service in obedience.
2 Timothy 4:2 Preach the word; be instant in season, out of season; reprove, rebuke, exhort with all longsuffering and doctrine.
They are fiery, representing the fiery trial that believers are subjected to.
1 Peter 4:12 Beloved, think it not strange concerning the fiery trial which is to try you, as though some strange thing happened unto you:
The taking of the live coal (the word of God / the gospel) from the altar (Christ) purges the iniquity of Isaiah, and he is sent to prophesy.
John 15:3 Now ye are clean through the word which I have spoken unto you.
Mark 16:15 And he said unto them, Go ye into all the world, and preach the gospel to every creature. 16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned (condemned).
The above explanation is speculative but it does fit the available scant information.
I hope you have found this helpful.
God bless you,