One of the books which first introduced me to Eastern Orthodoxy was Praying with the Orthodox Tradition by Stefano Parenti, translated by Paula Clifford.
This attractive volume (both in appearance and content) is, sadly, now out of print, though Amazon has plenty of cheap second-hand copies. The introduction is written by Bp Kallistos Ware, who concludes as follows (the words in quotation marks are from Fr Georges Florovsky):
“The goal of prayer is precisely to be with God always” … to make our prayer not just an intermittent activity, but a dimension present continually in all that we undertake – not simply something that we do from time to time, but something that we are the whole time. For this is what the world around us needs: not that we should say prayers occasionally, but that we should be at each moment a living flame of prayer.
As a sample of the prayers in the book, here is a prayer for the evening:
O Lord our God,
who live in unapproachable light,
in your great mercy
you have been our constant guide throughout this day
and have called us together
to give you glory at eventide:
hear the prayers
of your unworthy servants
and keeping us safe from the darkness of sin
give light to our souls,
that being ever in awe of you
and going forward in your light
we may glorify you in all things,
who in your unfailing love for all mankind
are the one true God.
For yours is the greatness,
the majesty, the power and the glory,
Father, Son and Holy Spirit,
now and ever,
to the ages of age. Amen.