Lord Krishna says the entire world is “spread by Me by my unmanifest form. All living entities are situated in Me, but I am not situated in them.” Arjuna, having heard this, has a query as to who are the best practitioners of yoga among the devotees, those who worship Him or those who only worship his unmanifest and indestructible form.
From this, it is obvious that God's unmanifest form is indestructible. God always exists in this form, and He incarnates. “Because O Bharata (Arjuna), whenever there is decline in religion, (and there is) ascendency of immorality, I incarnate myself (in this world).
Additionally, God incarnates Himself if a devotee so desires and deserves.”
Returning back to God's permanent form, we can assume this form to be an energy field. We are aware of various spectrums like 2G and 3G. Similarly, there are radio waves like AM and FM. These exist and do not clash or interfere with one another. These days we have many kinds of cellphone frequencies also. They all coexist. God's energy field is in addition to all these electric / electronic waves going around, and is all-pervading unlike other frequencies. God's energy field is unlike heat energy, which must influence. It is optional like a radio wave. You connect only when you tune in. God's energy field is unobtrusive.
Every one of us can take advantage of this by tuning in. All we need are our bodily faculties. One can do so by any process like meditating or praying. .God also answers through intuition, inspiration, dreams, etc. Physically also, God helps. People who are blessed with material "siddhis" (perfections) like producing an object from thin air use God’s spectrum.
God also has a permanent form. He lives with His devotees,those who have achieved liberation and desire God's physical company. He does so in His Narayan form.
However, gaining liberation is a long-term measure. For the time being, let us tune in to the big G spectrum and derive all benefits.