You are right in this is just PART of the gospel and people shouldn't be oppessed with it...it shouldn't become more important then the rest of the bible. But if you have truly studied the bible from beginning to end you will see satan all through the bible. He is called different names, just as Christ is too.
We see satan in Genesis tempting Eve...we see satan in Job allowed to torment Job and try to turn him from God, we even see many stories in the OT of God USING satan to His own means. We read about satan's fall from Heaven. Satan is probably mentioned in every single book in the bible.
When Jesus was here, He was constantly casting out demons, He was tempted by satan in the desert and the list just goes on and on, so I don't see how you can say satan is barely mentioned until Revelations.
He is called the Father of Lies, the Lawless One, the Dragon, the Seprent, Luficer, The Morning Star (not sure about that one) and on and on...
In the book of Ephesians chapter six quiet a bit is taught to us their about how to PROTECT ourselves from satan's attacks. Putting on the full armor of God...something we are do to everyday.
We don't need to be jumping at shadow by any means...satan has already been defeated by Jesus, so all we have to do is call on Jesus Name and satan flees. (in fact there is scripture saying to resistance satan and he will flee...of course for so many Christians they have no clue there is anything TO resistence..

)
Jesus taught quiet a bit also about satan and was even accussed at one point of using powers from satan to work His mircles.
Your comment just almost makes me wonder how much of the bible you have actually read.
I was not taught spirtual warfare in my church...so many act like satan isn't even real anymore...I read once the greatest trick satan ever did was make people believe he wasn't real! If you don't believe he is...you do nothing and are a sitting duck...so to speak.
But yes this is just ONE of the many things Christ wants us to be concerned with. I have not spent anymore time studying this then I have others parts of the bible. I am so glad I was lead to learn about it though, because it has helped my son so very very much.
Anyway I hope this helps you understand better...oh I wanted to post this scriptures:
Ephesians 6
10 A final word: Be strong with the Lords might power. 11 Put on
all of Gods armor so that you will be able to stand firm against
all strategies and ticks of the Devil.
12 For we are not fighting against people made of flesh and blood, but against the evil rulers and authorities of the unseen world, against those mighty powers of darkness who rule this world, and against wicked
spirits in the heavenly realms.
13 Use every piece of Gods armor to resist the enemy in the time
of evil, so that after the battle you will stil be standing firm.
14 Stand your ground, putting on the sturdy belt of truth and
body armor of Gods righteousness. 15 For shoes, put on the peace
that comes from the Good News, so that you wil be fully prepared.
16 In every battle you will need faith as your shield to stop the
fiery arrows aimed at you by Satan.
17 Put on salvation as your helmet, and take the sword of the Spirit, which is the word of God. 18 Pray at all times and on every occasion in the power of the Holy Spirit. Stay alert and be persistent in your prayers for all Christians everywhere.
(sorry I posted so fast I forgot to sign off)
God bless
whitestar