The gift of tongues is considered by Paul to be a true spiritual gift, but not for the benefit of the entire church. For that reason, Paul encourages the church to seek things that can be shared. He’s spent time talking about how the body works together and how love is the bond, so this is the next natural progression: if you are one body, bonded together, make sure you can worship together. Don’t separate yourselves. Then the body stays together, and worship becomes body work.