If your group meetings have gone flat, one of the easiest things you can do is take a break from your current study and focus on God.
Dietrich Bonhoeffer, in Life Together, describes a natural rhythm that he shared with students at the underground seminary he founded in Germany in the midst of Nazism. They came together to praise God and deepen their friendships.
Try it with your group when you want to set aside some time for focused prayer and worship.
Pray from the Psalms
As a group, read a psalm responsively, with the leader reading the odd numbered verses and the group reading the even numbered verses in unison. Make this reading a prayer to God.
Sing a Hymn
Ask someone in the group with musical ability to select and lead a worship song or hymn that will be commonly known to the group members.
Read the Scriptures
Ask one member in the group to select and read aloud a chapter from the Old Testament and another member to select and read aloud a chapter from the New Testament.
Sing Another Hymn
Again, have someone in the group with musical ability choose and lead a song that will be commonly known to the group members.
Spend a few minutes discussing and praying for needs of those in the group. Bonhoeffer recommends that the group leader be the one who prays aloud.
This one's pretty simple. Eat together and enjoy one another's company.