It is possible for all to pray with a congregation;
for many it is more suitable to pray with a single kindred spirit;
solitary prayer is for the very few.
(from the Ladder of Divine Ascent by St. John Climacus, Step 19:5)
Is St. John saying here that we should not pray by ourselves? Certainly not, for this would contradict the entire consensus of the Fathers of the Church regarding prayer, and even the words of Holy Scripture, which enjoin us to "pray without ceasing" (1 Thess 5:17)!
St. John himself, in another place, calls prayer "the queen of the virtues," who "cries with a loud voice and says to us: Come unto me, all ye that labor and are heavy laden, and I will give you rest" (Step 28:2).
No, St. John wishes to emphasize how difficult it is to pray alone, and how much easier it is to pray together. The context makes this clear, since Step 19 as a whole is about corporate prayer, with others.
St. John says that prayer is "the converse and union of man with God" (Step 28:1). So this is not just a matter of repeating the prayers in the prayer book. Prayer is a conversation with God, a lifting up of our mind and heart to Him. And how difficult this is!
How hard it is to say our prayers morning and evening, alone in front of our icons – and yet we feel that our prayer at home, feeble as it is, is sufficient. How much stronger our prayer is when two or three of us are gathered together, and Christ in our midst (Matt 18:20).
We are not saved as individuals, for it is our selfishness in pursuing our own individual agendas that separates us from God. We are saved by being united to His Body, by entering once again into union and communion with Him — and at the same time with each other. And the essence of this union is prayer. When we pray together, our prayers are stronger, supported by our mutual effort and by God's grace.
And so it is possible for all to pray when we gather together in Church, for our union with one another in the labor of prayer facilitates our union with God. So let us gather in Church and pray, as often as we are able!
In addition to this, it is suitable to pray with our loved ones — our spouse, our children — at home. It has been truly said that "the family that prays together stays together." Prayer is the tie that binds us to each other and to God. And this prayer is also easier than that solitary prayer.
So while continuing to labor in our personal prayers, let us not neglect to come together in prayer as often as possible both in church and with our families at home. As St. John assures us, this time spent in prayer together will be more fruitful (for all but the very few) than the time spent laboring in prayer alone.