Answer

In Jain Dharma, a deity cannot attain moksha directly from the heavenly state.

Even if a heavenly being develops detachment, right faith, and deep spiritual understanding, liberation is not attained from deva-gati. The soul must take birth as a human and then attain moksha through the complete destruction of karmas.

So yes, becoming human is required before final liberation.

Explanation

According to Jain teaching, there are four gatis, or states of worldly existence:

• Deva-gati — heavenly beings
• Manushya-gati — human beings
• Tiryanch-gati — animals, plants, and lower life forms
• Narak-gati — hellish beings

Among these, moksha is possible only from the human state.

Heavenly beings may have great pleasure, long life, subtle bodies, and extraordinary powers, but they are still bound by karma. Their heavenly existence is the result of punya karma, not liberation.

A deva can:

• Develop reverence for the Tirthankars
• Listen to true Dharma
• Gain or strengthen samyag darshan, right faith
• Feel detachment from worldly pleasures
• Prepare spiritually for a future human birth

But a deva cannot:

• Adopt the complete ascetic conduct required for moksha
• Destroy all ghati karmas in the way required for keval-jnan
• Attain final liberation directly from heaven

Why mindset alone is not enough

You are right that liberation depends deeply on the inner state of the soul. Jain Dharma gives great importance to bhav — inner attitude, purity, detachment, and awareness.

However, moksha is not only a matter of having the right mindset. It requires the full path of:

• Samyag darshan — right faith
• Samyag jnan — right knowledge
• Samyag charitra — right conduct

Complete right conduct, especially the highest form of renunciation and destruction of karmas, is possible only in human birth.

The heavenly condition has too much pleasure, attachment, subtle enjoyment, and limitations of that state. Even a spiritually advanced deva remains within samsar until the lifespan karma of that deva existence is exhausted.

Spiritual Understanding

In Jain Dharma, human birth is considered extremely precious because it has the right balance:

• Enough intelligence to understand Dharma
• Enough suffering to develop detachment
• Enough freedom to choose spiritual discipline
• The possibility of monkhood, tapasya, vows, and complete renunciation

Heaven is pleasant, but not the final goal. It is still samsar.

A deva with true detachment may create the causes for a spiritually powerful future human birth, where the soul can progress further and attain moksha.

Takeaway

A deity can become deeply detached and spiritually awakened, but cannot attain moksha directly from the heavenly state. In Jain Dharma, final liberation is attained only from human birth, through complete right faith, right knowledge, and right conduct.