1. Though other opening sentences are obviously possible, the classic opening sentence of Reformed and Presbyterian worship has been Psalm 124:8:
Our help is in the name of the Lord who made heaven and earth. Amen.
2. From the 1585 Reformed Liturgy of the Palatinate:
Grace, mercy, and peace, from God our Father, and his beloved Son Jesus Christ our Lord, and the fellowship of the Holy Spirit, be with us all. Amen.
The grace of the Lord Jesus Christ, and the love of God, and the communion of the Holy Spirit be with you all. Amen.
3. Adapted from the 1906 Book of Common Worship of the Presbyterian Church (U.S.A.):
The Lord is near to all who call upon him, to all who call upon him in truth. He will fulfill the desire of those who are in awe of him; he will hear their cry, and save them. Amen. (Psalm 145:18, 19).
4. Deuteronomy 4:39 (ESV)
Know this day and lay it to your heart that the LORD is God in heaven above and on the earth beneath; there is no other. Amen.
Examples 1-4 adapted and collected by M.D. Bush.