Ends and beginnings are important things. Paul's arrival at Jerusalem in Acts 21 marks an important end and an important beginning. It is the end of the church-planting journeys and the beginning of getting arrested, tried and proclaiming Jesus to rulers, authorities and nations in wholly new ways.
The end is marked by accounts of God being glorified by the planting of churches all over the place, and lots of people coming to Jesus. There is a lot of joy in the telling of what God has done. We don't do it nearly enough. Telling what he is doing among us and with us is faith-building.
The new beginning is caused directly by people hating Paul for saying that God includes Gentiles in his kingdom. False accusations are thrown, misrepresentations are rife, a riot and arrest and death threats ensue, because God is calling and using Gentiles and the people in Jerusalem hate them. In Acts 22:22, the people listen right up to the point where Paul says this, and then go mental, calling for his death for saying things they find so appalling.
God loves, calls and uses Gentiles. I need to be very careful before I place limits in my mind on who God may or may not lavish his love on and use. Perhaps another lesson here is that new beginnings sometimes come with conflict, resistance and riots. On their own these don't demonstrate that something new is necessarily of God, but they don't demonstrate that it isn't either.