1222
Śrīmad-Bhāgavatam
[ Canto 3, Ch. 28 ]
is propounded by Lord Caitanya as  acintya-bhedābheda-tattva . Everything is simultaneously one with and different from everything else. The cosmic manifestation created by the Supreme Lord by His material energy is also simultaneously different and nondifferent from Him. The material energy is nondifferent from the Supreme Lord, but at the same time, because that energy is acting in a different way, it is different from Him. Similarly, the individual living entity is one with and different from the Supreme Lord. This “simultaneously one and different” philosophy is the perfect conclusion of the  Bhāgavata  school, as confirmed here by Kapiladeva.
Living entities are compared to the sparks of a fire. As stated in the previous verse, fire, flame, smoke and firewood are combined together. Here the living entity, the material elements and the Supreme Personality of Godhead are combined together. The exact position of the living entities is just like that of the sparks of a fire; they are part and parcel. The material energy is compared to the smoke. The fire is also part and parcel of the Supreme Lord. In the  Viṣṇu Purāṇa  it is said that whatever we can see or experience, either in the material or spiritual world, is an expansion of the different energies of the Supreme Lord. As fire distributes its light and heat from one place, so the Supreme Personality of Godhead distributes His different energies all over His creation.
The four principles of the  Vaiṣṇava  philosophic doctrine are  śuddhādvaita , purified oneness,  dvaitādvaita , simultaneous oneness and difference,  viśiṣṭādvaita  and  dvaita . All four principles of  Vaiṣṇava  philosophy are based on the thesis of  Śrīmad-Bhāgavatam  explained in these two verses.
TEXT 42
सर्वभूतेषु चात्मानं सर्वभूतानि चात्मनि । 
    ईक्षेतानन्यभावेन भूतेष्विव तदात्मताम् ॥४२॥
sarva-bhūteṣu cātmānam  
 sarva-bhūtāni cātmani  
 īkṣetānanya-bhāvena  
 bhūteṣv iva tad-ātmatām
sarva-bhūteṣu —in all manifestations;  ca —and;  ātmānam —the soul;  sarva-bhūtāni —all manifestations;  ca —also;  ātmani —in the Supreme Spirit;  īkṣeta —he should see;  ananya-bhāvena —with equal vision;  bhūteṣu —in all manifestations;  iva —as;  tat-ātmatām —the nature of itself.