A prayer from Kneeling Vespers

Orthodox Christians do not kneel for prayers from Pascha until Pentecost. Following the canon of the first Nicene council, we don't kneel on Sundays, either. So Vespers on the evening of Pentecost is the first time since Pascha that we kneel; and some marvelous prayers are contained in these "Kneeling Vespers." Here's just one of them:

"Lord Jesus Christ our God, You have bestowed Your peace on mankind, and the gift of the Holy Spirit, to be with us even in thus life as a perpetual inheritance to believers never to be taken away. On this day You have sent this grace upon Your disciples and Apostles in a way more manifest, giving utterance to their lips by means of fiery tongues, so that every human race, hearing in our own language received the knowledge of God, and, illumined by the light of the Spirit, emerged from error as from darkness, and in the distribution of visible tongues of fire, and by extraordinary power, were taught faith in You, and were enlightened to speak of You, as of the Father and the Holy Spirit, as one Godhead, one power, one sovereignty.

As the reflection of the Father, the perfect and immutable likeness of His essence and nature, the source of salvation and grace, open the lips of this sinner and teach me how and for what I should pray. For You know the great number of my sins, yet Your compassion will overcome their enormity. For in fear I stand before You, casting my soul's despair into the sea of Your mercy. Govern my life, as You govern all creation by the unspoken word and the power of wisdom, calm haven of the storm-tossed, and make known to me the way in which I should walk.

Grant me the Spirit of wisdom in my thoughts, the Spirit of prudence in my ignorance. Let the Spirit of the awe of You, overshadow my deeds. Renew a steadfast Spirit in my breast, and let Your guiding Spirit make firm my errant mind, so that each day, led by Your good Spirit towards that which is profitable, I may be worthy to keep Your commandments, ever mindful of Your glorious and soul-­searching presence. Do not allow me to be beguiled by the world's corrupting delights, but rather to desire the enjoyment of future treasures. For You, Master, have said, that whatever we ask in Your name, we shall without fail receive from Your co-eternal God and Father. Thus I, too, the sinner, at the descent of Your Holy Spirit, beseech Your goodness. All that I have asked, grant me for salvation. Yes, Lord, You are the lavish giver of everything good, giving far in excess of what we ask. You are the compassionate and merciful One Who, though sinless, became sharer in our flesh, and bending in love towards those who bend the knee to You, You became the propitiation for our sins.

Now then, Lord, grant Your people Your mercies; hear us from Your heavenly dwelling place; sanctify them by the power of Your saving right hand; shelter them in the shadow of Your wings; do not spurn the work of Your hands. It is against You alone that we sin, but it is You alone we worship; we know no alien god to adore, not to stretch out our hands to any other deity, O Master. Remit our offenses, and as You receive our petitions on bended knee, extend to us all a helping hand. Accept our common prayer as a pleasing fragrance, rising up to Your blessed kingdom."