Of course I believe in angel they are documented in scripture. Only some of them sinned the others did not. There is no evidence that those who sinned are offered a savior or salvation. In fact scripture suggests they are not, they have made their choice. The offer of salvation through Christ is offered only to mankind in the Bible. If there is anything for angels we are not told about it.
What's with the "scripture suggests"? Are you pulling a Martin Luther, e.g., "be a sinner, and sin boldly"?
Where is that in scripture?