Answer

In Jain Dharma, Siddhas are higher in the final spiritual state, because they are completely liberated souls who have left the cycle of birth and death forever.

However, Tirthankaras are supremely revered in the worldly realm, because they not only attain liberation but also re-establish the Jain Sangh and teach the path of moksha to countless souls.

Explanation

A Tirthankara is an Arihant Bhagwan who:

• Destroys the four ghati karmas
• Attains kevaljnan
• Preaches the path of liberation
• Establishes the fourfold Jain Sangh
• Eventually attains moksha and becomes a Siddha

A Siddha is a liberated soul who:

• Has destroyed all eight karmas completely
• Has no body
• Does not take birth again
• Dwells eternally at Siddhashila
• Exists in infinite knowledge, perception, bliss, and energy

So, every Tirthankara ultimately becomes a Siddha after nirvana.

Spiritual Understanding

In the Namokar Mantra, we bow first to Arihantas and then to Siddhas:

• Namo Arihantanam
• Namo Siddhanam

This does not mean Arihantas are spiritually “more liberated” than Siddhas. Siddhas are fully liberated and have no remaining karmas. But Arihantas are placed first because they are living omniscient teachers who show the path of liberation to others.

Takeaway

Siddhas are higher as fully liberated souls.
Tirthankaras are higher in reverence as world-teachers who guide others to liberation.

Both are supremely worthy of worship in Jain Dharma.