This song serves as a launching point for the divine service experience and should subsequently be upbeat, powerful, praise-filled, and full of energy. Some examples of always-appropriate opening hymns include: Praise Thou the Lord; A Mighty Fortress Is Our God; Holy, Holy, Holy; To God Be the Glory, and Rejoice, the Lord is King!
Similar to the worship songs, the opening hymn does not need to be connected to the Bible verse or sermon theme (although it certainly can be powerful when the opening hymn includes the characteristics above and it’s connected with the theme/verse). Consider that at this point in the divine service, the sermon message has not yet been delivered, and so it does not necessarily need to be communicated through the opening hymn. The focus here is on greeting God and giving Him praise!