We all know relationships are messy, they do not fit into neatly contained areas, or stay within certain boundaries, they are living breathing, shifting, changing, growing, adapting realities. If a relationship stays the same over years and years then we would conclude that there is something wrong with that relationship.
As churches are composed of people in relationships, relationships that are living, breathing, shifting, changing, growing and adapting realities then we should expect church to be similar. Relationships are messy church should be too. Church should should adapt as its members go through different stages of life. Some things will always remain the same - the gospel will always be central and its teaching always a primary focus. But so much else can bend and flex - timings, songs, groups, music, mid-week activities and so on are all things that can and should flex.
And home groups ought to reflect that relational reality - are all our home groups the same? Is it a monoculture, if so why because our churches aren't. Are they all at the same time? Because our people will not all be at their best or most attentive at that same time - it is not a monoculture. There is a sense in which we want to have people who are different together- that as Ephesians has been teaching is one of the joys of church. But home groups ought to reflect the relationships of those which form it - do a few people in the group struggle meeting at 7.30pm? What time could the group flex to? How about 5.30pm or 6pm with a shared meal? Is the groups composed of a number of families - could they meet all together for a shared meal and parents take it in turns looking after the children while others study the bible? Then when the children are old enough they simply join the bible study.
Why do we rule out home group on a Saturday? If it works for some then great.
But I think there is more to it than that, home groups should reflect the community they are based in, but that is something else for another day.