FWIW -- (from a lay person's perspective)
The church of which I'm a member (
www.lighthouseministries.org ) has
BOTH a Sunday School
AND Small Groups---which we call our Life Groups. (The website has a link that goes into detail about our Life Groups.)
We've gone through several changes over the past 10 years or so. The biggest change was merging with another congregation back in 2009 --- due largely to the fact that our pastor had health issues & also to his having felt the need to step aside from his pastoral duties to pursue more of a focus in various other areas of ministry to which he felt the Lord was calling him [
www.compassionatehope.org ].
Our Life Groups meet together at various places (usually at a family's home) and at different evenings of the week. Each Life Group has its own personality, and no two of them operate exactly the same. EXAMPLE: My particular Life Group usually has prayers over the prayer requests presented at the beginning of the meeting followed by a Bible devotion led by a different man each week (w/ thoughts, comments, etc., following).
I love my Life Group for so many different reasons.
They rallied around me when I suffered a rather debilitating stroke in 2011; they ministered to a pastor & family who'd suffered much from another church in the area [FYI--He's now serving the Lord in the Rochester NY area]; they were one of the first groups to respond in many different ways when our Christian school facilities were severely damaged in May 2010; and I could go on and on.
Our Life Groups aren't perfect :smilewinkgrin:--just made up of saved sinners doing life together, and with our Lord's help, being the hands and feet of Jesus for each other and for a lost and dying community around us. :thumbsup: