The present human incarnation is the only way
Datta means God available for souls. He is available in the human form with materialized body since human beings are with materialized bodies. The same God is available in energetic body to angels and to the departed souls from the earth, since both angels and the departed souls are in the energetic bodies.
The angels are the souls in permanent energetic bodies, whereas the departed souls exist in the energetic bodies till they take the re-birth. The present alive human form of God is most relevant to the present alive human generation. Therefore, energetic form of God and also the past human form of God are irrelevant to the present human beings.
Hence, the fruits of devotion are given by the contemporary human incarnation only to any present alive human being. Before giving the fruit, you will be tested in two aspects.
1. The first aspect is the importance you give to God above all your present bonds, which are mainly with your wealth (Dhaneshana), your wife or husband (Dareshana) and with your children (Putreshana). Another main bond is also regarding your attachment to your body and life (Deheshana and Praneshana). The first aspect deals with the position you give to God beyond all these five bonds.
2. The second aspect is about your recognition of contemporary human incarnation of God through analysis.
The first aspect is called as Devotion (Bhakti Yoga) and the second aspect is called as Knowledge (Jnana Yoga). Of course, each of these two aspects always pervades the other aspect. The basis of establishment and development of Devotion is analysis or Knowledge. Similarly, the result of analysis or knowledge is always establishment and development of devotion. Both Devotion and Knowledge are essential for your success in the examination conducted by Datta or contemporary human incarnation. Without examination, the fruit cannot be given.
You cannot get the certificate of the degree without the final written examination. Devotion and Knowledge are essential requirements for the test conducted by Datta as paper and pen are essential requirements for the written examination.