The Trisagion Prayers are the "bread and butter" of Orthodox worship. We say these prayers as part of our morning and evening prayers. It's good to memorize these prayers. There is power in the ancient words. I have them taped to my wall, next to my icons.
In the name of the Father, and of the Son and of the Holy Spirit. Amen.
O Heavenly King, Comforter, Spirit of Truth, Who are everywhere present and filling all things, Treasury of good gifts and giver of life; come and abide in us, and cleanse us of all impurity and save our souls, O Good One.
Holy God, Holy Mighty, Holy Immortal, Have mercy on us. Holy God, Holy Mighty, Holy Immortal, Have Mercy on us. Holy God, Holy Mighty, Holy Immortal, Have mercy on us.
Glory to the Father, and to the Son, and to the Holy Spirit, now and ever and to the ages of ages, Amen.
Most Holy Trinity, have mercy on us, O Lord wash away our sins, O master, pardon our transgressions. O Holy One, visit and heal our infirmities, for Thy Name's Sake.
Glory to the Father and to the Son and to the Holy Spirit, now and ever, and to the ages of ages, Amen.
Our Father, Who art in heaven, hallowed by Thy Name. Thy Kingdom come. Thy will be done, on earth as it is in heaven. Give us this day our daily bread. And forgive us our debts as we forgive our debtors. And lead us not into temptation, but deliver us from the evil one. For Thine is the kingdom, the power and the glory, of the Father, and of the Son, and of the Holy Spirit, now and ever, and to the ages of ages, Amen.