The word 'God' can be translated in many ways. It can mean the nirguNa Brahman, Who is described as the 'drasta sAkshi kevalo nirgunas cha : just Witness of every activity), or to the Saguna Brahman or Ishvara (According to the Advaita-Vedanta, He is the Nirguna Brahman seen from within the Maya). The three gunas make Him do three activities simultaneously and ceaselessly : Creation by Rajo-Guna, Preservation by the Sattva-Guna and Destruction by the Tamo-guna.
The above is clearly mentioned in Srimad-Bhagavatam (10/2/28)
tvamekah evAsya satah prasutis tvam sannidhAnam tvam anugrahas cha/tvan mAyayA samvritachetasas tvAm pashyanti nAnA vipaschito ye//
meaning: O God ! You alone create, preserve and destroy the worlds. Those who are deluded by Maya sees many forms of you [like Brahma, Vishnu, Shiva etc], but the wise ones know that you are always One.
The svarupa of God according to Srimad-Bhagavatam (3/26/3) is
•anAdir AtmA purusho nirgunah prakriteh parah/pratyagdhAmA svayamjyotir vishvam yena samnvitam//
meaning : God (Purusha) is originless, devoid of any quality (nirguNa), all-pervading and infinite. He is always separate from the prakiti (consisting of the three gunas that create, preserve and destroy), is self-effulgent. So here God in His real svarupa does nothing.
That the God works ceaselessly has been mentioned in the Gita:
3.23 For, O Partha, if at any time I do not continue vigilantly in action, men will follow My path in ever way.
3.24 These worlds will be ruined if I do not perform action. And I shall become the agent of intermingling (of castes), and shall be destroying these beings.
By the way, Creation did NOT stop. This universe in finite as is time and this three activities are taking place in anything material continuosusly,Science including biology accept especially the latter.
Shiva-PurAna mentions that Ishvara is Lord Shiva Himself. He assumes five forms:
Sivo Mahaswarachiva Rudro Vishnuh Pithamaha /
Sansara Vaidyah Sarvajnah Paramatmeti Mukhyataha /
Namashtaka midam nitya Sivasya Prati padakam/
So the five forms are Shiva, Mahesvara, Rudra, Vishnu and BrahmA (PitAmaha).
He assumes these five forms to perform five functions known as the 'Pancha-Kritya-s:Creation or Srishti, Preservation or Sthiti, Destruction or Laya, Tirobhava or Nigraha (concealment and Revival) and Anugraha (Providing salvation by grace).These five are the constant activities of the Ishvara.
As BrahmA He does creation, as Vishnu He does preservation, as Rudra desrtruction, as Maheswara concalment and revival, as Shiva showering of grace and giving liberation.
Reference: http://www.kamakoti.org/kamakoti/details/shivapuranam38.html
That God does do 'anugraha' and 'nigraha' is accepted by Srimad-Bhagavatam also (10/16/59).
According to the Devi-Bhagavatam (Canto 5, chapter 8, slokas 59
tathA eshA devakaryaArtham arupA api svalilayA/karoti vahurupAni nirguNA sagunAni cha// meaning the Supreme Goddess is beyond all qualities [ and so inactive]. But to perform works for the welfare of the gods, She assumes various forms by various qualities (guNas).
According the Devi-Vhagavatam, MahamAyA is Brahman, ParamAtmA and God Herself (Reference: Sri Sri Chandi,Udbodhan, page 48).
According to the KAlikA-PurANa,
God is called MahamAya.She covers the knowledge of the jiva as soon as the jiva is born.She binds them with attachment and greed (mamatva and moha) according to the child's impressions (sanskaras) of the previous births,She constantly hyponises the jiva by attaching them to thoughts, dsires and sensual pleasures and injects in them anger, lust and attractions.
So the above are the never-ending activities of Mahamaya, Who is God according to the KAlikA-purANa (Reference : Ibid. page 49).
I found this question from OP in a comment in response to another answer:
"I mean god in physical appearance like before ...why not now like before?"
This 'like before' has no meaning to me. In Hinduism God is NOT an individual residing somewhere with some particular form---- God is eternal and unfathomable and changeless in essence. He constatly assumes different forms for different activities. This is especially true for the Sanatana Dharma. I think the above quotations make it clear that such a question is without any basis with respect to our holy scriptures. Yes, there are mentions of different lokas like Golaka, Vaikuntha, Shivaloka, Deviloka etc etc Where a particular form of God is said to reside with consort and live playfully.I think a moment's thought makes it clear that NO such loka can be accepted as THE Supreme Abode of GOD.It varies with the belief of the devotee.So we can never say that God reides at some particular loka and do some particular thing and not reside in the other lokas and not doing other things.
Please see the concept of God from two puranas:
Siva is not just the god of destruction, dwelling on the Himalayas or the cremation ground. He is the embodiment of renunciation and destruction of all evil. He is the personification of contemplation and divine consciousness. He is ‘the one Brahman, without a second, the All’ (Skanda Purana 4.1.10.126)
Is Visnu merely the lord of protection and preservation? He is the embodiment of the divine Principle that permeates the entire universe in which the world-play of creation, preservation and dissolution is enacted. He ‘abideth in all.’ He is ‘all’. He assumes all forms (vide Vishnu purana 1.12.71)
So a minute study reveals that both are in fact just different forms of the SAME God.
UPDATE
Which demons got killed today?
According to the saints like Sitaramdas Omkarnath, the demons are actually different desires, passions and attractions that make the aspirants deviate from the spiritual path. As Sri Krishna says in Gita
10.11 Out of compassion for them alone, I, residing in their hearts, destroy the darkness born of ignorance with the luminous lamp of Knowledge.
This is the essence of the 'Demon-Killing' lila.Those who are walking along the spiritual path sincerely must have been getting God's grace with the demons in them getting killed by Him regularly. But it is kniwn only to the devotee and his/her Lord. This can be termed as His 'Anugraha'.
On the otherhand, Gita also mentions
16.19 I cast for ever those hateful, cruel, evil-doers in the worlds, the vilest of human beings, verily into the demoniacal classes.
This can be termed as His 'Nigraha'.
So the demons are getting proper treatment from Him at each instance. And from a broader perspective, He Himself is becomeing demon or evil and He Himself is slaying --- all is the Divine Play of the One.'Ekam vedam vibabhuv sarvam'.