Īśāvāsyopaniṣat 12, 13 and 14

अन्धन्तमः प्रविशन्ति येऽसम्भूतिमुपासते। ततो भूय इव ते तमो य उ सम्भूत्यां रताः ॥१२॥

Those who worship the denial of becoming enter blinding darkness. To a greater darkness, it seems, go those who delight in the becoming.

अन्यदेवाहुः सम्भवादन्यदाहुरसम्भवात्। इति शुश्रुम धीराणां ये नस्तद् विचचक्षिरे ॥१३॥

The wise say that one thing results from the becoming, and another from the un-becoming. Thus, we have heard from the sages who explained this to us.

सम्भूतिं च विनाशं यस्तद्वेदोभयं सह। विनाशेन मृत्युं तीर्त्वा सम्भूत्याऽमृतमश्नुते ॥१४॥

One who knows simultaneously the process of both the becoming and the un-becoming, transcends death through un-becoming, and attains immortality through the becoming.

Īśā.Bhāshya 14

A testimonial from Kurma Purana is quoted to drive the point. One who knows the instrumentality of Lord Vishnu in the process of becoming, and un-becoming, who understands the hierarchy of principles and their governing deities, and who knows Lord Vishnu as the supreme principle embodied with all auspicious qualities, is released from bondage.

एवं सृष्टिकर्तृत्वं नाङ्गीकुर्वन्ति ये हरेः। तेऽपि यान्ति तमो घोरं तथा संहारकर्तृताम्॥ नाङ्गीकुर्वन्ति तेऽप्येवं तस्मात् सर्वगुणात्मकम्। सर्वकर्तारमीशेशं सर्वसंहारकारकम्॥

"Thus, those who do not accept Hari's role as the creator also enter terrible darkness, as do those who reject His role as the destroyer, those who do not accept Him as the one who embodies all qualities, the creator of all, the Supreme Lord of lords, and the cause of all destruction.

यो वेद संहृतिज्ञानाद् देहबन्धाद् विमुच्यते। सुखज्ञानादिकर्तृत्वज्ञानाद् तद्व्यक्तिमाव्रजेत्॥

One who knows the process of dissolution (saṁhṛti), through such knowledge, is freed from the bondage of the body, and attains knowledge and happiness through the knowledge of that supreme personality's instrumentality."

सर्वदोषविनिर्मुक्तं गुणरूपं जनार्दनम्। जानीयान्न गुणानां च भागहानिं प्रकल्पयेत्॥

One should know Lord Janardana (the protector of beings), who is free from all faults and whose form consists of supreme qualities. Moreover, one should not conceive of any diminution or loss in His qualities.

न मुक्तानामपि हरेः साम्यं विष्णोरभिन्नताम्। न वै प्रचिन्तयेत् तस्माद् ब्रह्मादेः साम्यमेव वा॥

One should not think that the liberated souls are equal to Hari or identical to Vishnu. Therefore, one should not conceive equality with Brahma or others deities either.

मानुषादिविरिञ्चान्तं तारतम्यं विमुक्तिगम्। ततो विष्णोः परोत्कर्षं सम्यग् ज्ञात्वा विमुच्यते॥

Understanding the gradation of hierarchy starting from humans and ending with lord Brahma is the path to liberation. Thereafter, realizing the supreme excellence of Vishnu properly, one attains liberation."

इति कौर्मे ॥१२-१४॥

- stated thus in the Kurma Purana.

Note:

The word 'sambhava' i.e. becoming or coming in to existence, and 'asambhūta' i.e. un-becoming, to dissolve, to go out of existence are profound metaphysical concepts. After tackling the dual aspect of epistemology, the focus here is on the metaphysical aspect of becoming and un-becoming. The process of becoming and un-becoming are identified as two distinct aspects of reality and understanding both the aspect is necessary.