'Are we alone in the Universe?'
Only the spiritually-alienated Twentieth Century could have thought up such an absurd question.
Once upon a time everybody knew that we are most certainly not alone. We are with God through His Word, His Son Who bears our human nature and Who by the Holy Spirit sent from the Father is with us, present in His Creation. Unto Him 'all power is given in heaven and earth' and He is with us 'always even unto the end of the world' (Matthew 28, 18-20). And God made not only 'Earth', that is all things visible, but also 'Heaven', all things invisible. And according to the Liturgy both are 'full of His glory'.
The invisible world of Heaven is full of angels. Of course it is also true that some of them fell and became demons. These too are invisible, but they inhabit not Heaven but Hell, the self-created place of the rejection of the Love of God.
As regards the extent of God's visible Creation, we are unable to say very much. With our small created human minds, what can we possibly know of this immense Universe, this Creation of the Eternal God? We only know that it would seem to extend for billions of light-years and contains billions of stars. We only know that at present there is no other life in our solar system. And that whatever may exist in other solar systems, we can be sure that it is not menacing to us, for it is all the work of God. The monsters from outer space of contemporary imagination are merely the monsters that lurk in the darkness of our fallen and now dechristianised human minds, they are the demons of our sinfulness and no more.
Are we alone in the Universe? No, there is the penetration of Heaven into Earth, of the invisible into the visible. Thus not only is the Holy Trinity spiritually present in the created Universe of Time and Space, but there are the angels, and also other spiritual presences in the Universe. There are those billions of departed souls, our forefathers and foremothers whose souls still contact us, and in particular there is the spiritual presence of the Saints who protect us and guide us and help us in our daily lives.Why is the Universe so huge? Surely in such an immense Universe there must be other human life on other planets? Of course we can speculate that there may be other planets where men and women have always lived in Paradise, never having fallen from Grace and Glory. But this is mere speculation. In fact given the present state of outward human knowledge ('scientific knowledge') we cannot answer the question of the possible presence of other human life on other planets. All we can say is that the Universe is part of the Mystery of God and that the outer Creation, ('Earth' in theological language) is a visible symbol of the inner Creation ('Heaven' in theological language). Thus the Sun is the symbol of the Creating Word of God, the Moon of the Mother of God, and every star of night is the sign of an angel or saint.
And what is the Independence Day of Orthodox Christians?
It is the Day of our release from the material determinants of this world. It is that long-awaited Day when our souls leave our bodies and we shall be free at last, independent of all the material constraints and passions forced on us by our fallen natures and bodies and all the present material world.
Even so, come, Lord Jesus!
More details of the book "The Lighted Way" and where to buy it, can be found on The English Orthodox Trust page of this site.