Srimad-Bhagavatam: Canto 8 - Chapter 1 - Verse 3
यद्यस्मिन्नन्तरे ब्रह्मन्भगवान्विश्वभावन: ।कृतवान्कुरुते कर्ता ह्यतीतेऽनागतेऽद्य वा ॥ ३ ॥
yad yasminn antare brahmanbhagavān viśva-bhāvanaḥkṛtavān kurute kartāhy atīte ’nāgate ’dya vā
O learned brāhmaṇa, kindly describe to us whatever activities the Supreme Personality of Godhead, who created this cosmic manifestation, has performed in the past manvantaras, is performing at present, and will perform in the future manvantaras.
In Bhagavad-gītā the Supreme Personality of Godhead said that both He and the other living entities present on the battlefield had existed in the past, they existed at present, and they would continue to exist in the future. Past, present and future always exist, both for the Supreme Personality of Godhead and for ordinary living entities. Nityo nityānāṁ cetanaś cetanānām (Kaṭha Upaniṣad 2.2.13). Both the Lord and the living entities are eternal and sentient, but the difference is that the Lord is unlimited whereas the living entities are limited. The Supreme Personality of Godhead is the creator of everything, and although the living entities are not created but exist with the Lord eternally, their bodies are created, whereas the Supreme Lord’s body is never created. There is no difference between the Supreme Lord and His body, but the conditioned soul, although eternal, is different from his body.