I will finally address the fourth of the four points of RC-EO disagreement related to the teachings of EO St Gregory Palamas (1296-1359), which is, in its RC and EO versions:
C4. Beatific Vision: Pope Benedict XII in his Constitution "Benedictus Deus" (1336) defined that saints in Heaven "see the divine essence with an intuitive vision and even face to face, without the mediation of any creature by way of object of vision; rather the divine essence immediately manifests itself to them, plainly, clearly and openly, and in this vision they enjoy the divine essence." The Ecumenical Council of Florence (1439) confirmed it in a more succint manner, defining that saints in Heaven "clearly behold the triune God as he is".
On the other hand, RC St Thomas Aquinas distinguishes between vision and comprehension. Creatures in the beatific vision see the whole, but they do not comprehend it wholly. Only God wholly comprehends God, as no created intellect can comprehend the divine essence (according to Aquinas, not even the glorified soul of Jesus, although I do not know whether this specific point is generally accepted RC doctrine or just Aquinas' personal opinion.)
O4. Saints in Heaven do not see the divine essence, only the divine energies.
Of course, one way to solve the disagreement would be to prove that there is no ontological distinction between the divine essence and energies, i.e. to solve point 2. However, I will proceed the other way.
There are two NT passages that are most relevant regarding this issue:
At present we see indistinctly, as in a mirror, but then face to face. At present I know partially; then I shall know fully, as I am fully known. (1 Cor 13:12)
Dear friends, now we are children of God, and what we will be has not yet been made known. But we know that when he appears, we shall be like him, for we shall see him as he is. (1 Jn 3:2)
Most clearly, the statements that "I shall know fully, as I am fully known." and that "we shall see him as he is" are not compatible with Palamas' doctrine that the blessed do not see the divine essence. Moreover, the Pauline statement seems at first sight even incompatible with Aquinas' restriction that the blessed do not comprehend the divine essence, because God certainly does comprehend mine!
Regarding the possible objection that the two quoted passages refer to the vision of Jesus in glory like (Rev 1:13-16) and not to the vision of God, an objection which seems to be reinforced by the Pauline reference to God "whom no human being has seen or can see" (1 Tim 6:16), I answer:
First, that the interpretation of the two passages quoted first as referring to the vision of God and not (only) of Jesus in glory is the most logical by far is clearly seen when we take into account that:
1. It does not make sense to refer to the future vision as the two passages do if it is only of a (however much) glorified human nature.
2. The last noun before "he" and "him" in the second passage is "God" (which unequivocally refers to the Father as it is used in the expression "children of God"), and therefore those pronouns refer to God.
Second, that St Paul's statement at (1 Tim 6:16) refers only to human beings on earth is clearly seen when we read it in conjunction with Jesus' statement: "Blessed are the clean of heart, for they will see God" (Mt 5:8). And at this point it may be useful to compare the interpretations of both statements on the vision of God, regarding:
- what is meant by "God", and
- the circumstances of the vision or lack thereof.
xx -- The clean of heart will see God (Mt 5:8). -- No man has seen or can see God (1 Tim 6:16).
RC -- Essence, in Heaven. -- Essence, on earth.
EO -- Energies, in Heaven and on earth. -- Essence, on earth and in Heaven.
While the EO interpretation of "God" in (Mt 5:8) as referring to the divine energies and in (1 Tim 6:16) as referring to the divine essence is clearly arbitrary, the RC interpretation of (Mt 5:8) as referring to Heaven and of (1 Tim 6:16) as referring to earth is completely logical as it derives directly from the verbal tense used in each statement:
(Mt 5:8): "will see" = future => in Heaven
(1 Tim 6:16): "has seen or can see" = past and present => on earth