Surely you remember that the Bible is made up of different genres of writing? For example, Psalms are poetic, Kings and Acts narrative style, Jesus sometimes used parables. Sometimes hyperbole is used. Revelation and Daniel are apocalyptic. It's important to look at the literary genre of the writing, then the historical context, and what was the intention of the author. Often the Bible will state what a particular symbol represents.
The Rev 2:20-23 passage you mentioned earlier is one of the seven letters Jesus writes to the churches - in this case, Thyatira. A larger quote is more helpful: (v.19-25):
And to the angel of the church in Thyatira write: ‘The words of the Son of God, who has eyes like a flame of fire, and whose feet are like burnished bronze.
^See here the use of similes, 'like' a flame of fire, 'like' burnished bronze. Not actual fire nor bronze. Both these similes suggest judgement from usage elsewhere in the bible, too long to go into here. Jesus calls himself 'Son of God' here to contrast with local claims that Apollo and the emperor were “sons of god" indicating only Jesus has the divine authority.
‘I know your works, your love and faith and service and patient endurance, and that your latter works exceed the first. But I have this against you, that you tolerate that woman Jezebel, who calls herself a prophetess and is teaching and seducing my servants to practice sexual immorality and to eat food sacrificed to idols. I gave her time to repent, but she refuses to repent of her sexual immorality. Behold, I will throw her onto a sickbed, and those who commit adultery with her I will throw into great tribulation, unless they repent of her works, and I will strike her children dead. And all the churches will know that I am he who searches mind and heart, and I will give to each of you according to your works. But to the rest of you in Thyatira, who do not hold this teaching, who have not learned what some call the deep things of Satan, to you I say, I do not lay on you any other burden. Only hold fast what you have until I come."
What do we know about the church in Thyatira? It was a real church, situated between Pergamos and Sardis. It was a Macedonian colony, founded by Alexander the Great after the overthrow of the Persian empire. The Macedonian colonists appear to have introduced the worship of Apollo, honoured as the Sun-god. People there were from mixed heritage: Asiatics, Macedonians, Italians, and Chaldeans.
Jesus begins by praising the works of the church there, however the church is condoning this 'Jezebel' person, which they should not have done. In the Old Testament Jezebel led Israel into Baal worship and immorality, Jesus uses the same name here, likely referring to similar teaching rather than the actual name of the person. The church in Thyatira must repent of this association otherwise they'll undergo severe judgement ('throw' being a future action). 'Her children' is not literal children, but refers to those who followed Jezebel's (Satanic) teachings and did not hold to the faith. Optimistically the letter ends indicating there is a remnant in the church who do not hold to the teachings of this Jezebel, and Jesus encourages them to hold fast to their faith until He returns. (And yes I am fully aware of how long ago this was and that He has yet to return).
Note: I've used my pastor's sermon on this passage as well as commentaries to try to explain this. Also other denominations may interpret this differently. Some equate the church at Thyatira to the Catholic church, for example. Since these are future prophecies we won't know for sure until it happens.