What does Gita say about the worship of demi Gods?

In Gita lord Krishna forbids people from the worship of many Gods. He says that men fail to understand that the Pramatma is the only one who needs to be worshiped. People who have lost their spiritual sense take shelter of demigods for immediate fulfillment of material desires. .So under the influence of their prakriti(the sanskars that they have adopted over several lifetimes(according to Gita all living persons form as a result of sanskars they have adopted over several lifetimes)) they worship other Gods.
          kämais tais tair håta-jïänäù prapadyante ’nya-devatäù
        taà taà niyamam ästhäya prakåtyä niyatäù svayä...........B.G.CH7 SLOK 20
He then states that as soon as one desires to worship some demigod, I make his faith steady so that he can devote himself to that particular deity. It is because there are no such entity as demigods who could steady the devotion of these devotees, so I myself have to do this.
        yo yo yäà yäà tanuà bhaktah sraddhayärcitum icchati
       tasya tasyäcaläà çraddhäà täm eva vidadhämy aham...B.G.CH7 SLOK 21

He then says that endowed with such a faith, he endeavors to worship a particular demigod and obtains his desires. But in actuality these benefits are bestowed by Me alone.Who satisfies their desires? I. The result of their faith is the satisfaction of their desires and not reward by their worshiped demigod.

         sa tayä sraddhayä yuktas tasyärädhanam ihate
         labhate ca tataù kämän mayaiva vihitän hi tän...B.G.CH7 SLOK 22


Now the natural question arises what is the problem of their devotion to other gods? since  their desires are  getting fulfilled.So lord krishna says in the next sloka.......

             

   antavat tu phalaà teñäà tad bhavaty alpa-medhasäm

   devän deva-yajo yänti mad-bhaktä yänti mäm api..B.G.CH7 SLOK 22

Men of small intelligence worship the demigods, and their fruits are limited and temporary and prone to destruction. Those who worship the demigods go on to unite with demigods, so demigods are also temporary and prone to destruction, but My devotees ultimately unite with me and complete peace and freedom from this mortal illusionary world..Lord krishna again brings the topic of demigods in chapter 9 and says those who worship demigods indirectly worship me but they do so in a wrong way..

        ye ’py anya-devatä-bhaktä yajante çraddhayänvitäù

        te ’pi mäm eva kaunteya yajanty avidhi-pürvakam..B.G.CH 9 SLOK 23

He again says in chapter 8 everybody begining from bramha to the lowest creature are bound by the cycles of life and death But one who attains to me , O son of Kunté, never takes birth again.....

     ä-brahma-bhuvanäl lokäù punar ävartino ’rjuna

     mäm upetya tu kaunteya punar janma na vidyate..B.G.CH 8 SLOK 16

So from these slokas from the pious bhagbat gita it is clear that there are no such individuals as demigods. The   divinity is within us. By cultivating which we can reach the sumpreme spirit(Pramatma). Even lord krishna is not a god. Rather he is a yogi who has united with the God; and now from his mouth it is the god who is speaking........OM TATSAT

     

   

     

     

What does Gita say about incarnations?

Lord Krisna clearly states in Gita that whenever there is adharma predominating on the dharma and the dharma in intself isn't able to fight with adharma then I appear and stand by the side dharma and help it to conquer over the adharma...
                     .yadä yadä hi dharmasya glänir bhavati bhärata
                    abhyutthänam adharmasya tadätmänaà såjämy aham..B.G.CH4 SLOK 7


                       pariträëäya sädhünäà vinäçäya ca duñkåtäm

                   dharma-saàsthäpanärthäya sambhavämi yuge yuge .B.G.CH4 SLOK 8

But these slokas doesn't mean that God appears in the outside world. Whole of Gita is concerned only with our innerself. The yudha/war that is going on; the incarnation of God is all happening or happens in the innerworld of the yogi. The yug here doesn't refer to satya,treta, dwapar and kali or any other yugs but the yugas occour in the inner-world of the yogi. To understand this concept more clearly he states in the next sloka itself that only tatva darshi are able to see me with their eyes. 

                 janma karma ca me divyam evaà yo vetti tattvataù

                tyaktvä dehaà punar janma naiti mäm eti so ’rjuna..B.G.CH4 SLOK9

So it becomes clear that if there was actual incarnation everybody on earth could see it. But only tatva darshis are able to see me. Because my incarnation occour in their heart whenever they cannot cut away from illusionary world and adharma(like kam,krodha etc..).Lord Krishna says the same thing for other Gods also. According to him there are no such thing as god.There is two things that is true- one is atma and other is paramatma...om tatsat..                          

                      

                 

What is the main message of Gita?

The main message that comes out of Gita is the message of "NISKAM KARMA YOGA"(i.e. to do our work withot having any expectaion of the result.). Gita says that if we properly indulge in the act of "NISKAM KARMA YOGA" we will be able to attain moksha. But fellow seekers beware.. this karma or work to be done is not the karma we indulge in everyday life.Yogeswara Krisna himself says in Gita only karma that has to be done is the Niyat karma...
                                 niyataà kuru karma tvaà karma jyäyo hy akarmanah
                                saréra-yäträpi ca te na prasiddhyed akarmanah ...BHAGBAT GITA..CH3-SLOK 8
Now the question arises what his Niyat karma to this he says in the next sloka....
                            yajïärthät karmaëo ’nyatra loko ’yaà karma-bandhanah
                            tad-arthaà karma kaunteya mukta-saìgaù samäcara...BHAGBAT GITA..CH3-SLOK 9
So the niyat karma that needs to be done is the act of yagna..So, what is yagna? Where does it come from what does it give? It is the act which one has to learn from a spiritual master..by which You will be slowly and steadily advance to me and when you gain complete access to me you will be the reciever of trancedental knowledge. In other words yagna is the act of aradhana that is the worship of god with single minded devotion.While we are indulged in this act of aradhana we should always remember that we shouldn't demand anything or should not have any want against it. We shouldn't even ask for moksha..we will get what we deserve in due time.....OM TATSAT