Colossians 4:15-16

‘Salute the brothers who are in Laodicea, and Nymphas and the church that is in their house. And when this letter has been read among you, cause that it be read also in the church of the Laodiceans, and that you also read the letter from Laodicea.'

He sends greetings to the Laodiceans in the letter, probably partly because he wanted the letter read in the Laodicean church and wanted them to know of his warm affection for them. This letter and his letter to the Laodiceans are to be exchanged between the churches for mutual benefit. The letter to the Laodiceans may have been a copy of the letter to the Ephesians, and if so it was probably not yet written, for Ephesians is a development on the Colossian letter. But he may have mentioned it because it was his intention to send both at the same time, once Ephesians had also been written. Alternately it may simply be a letter that was later lost.

‘Nymphas and the church that is in their house.' It is debated whether Nymphas is a man or is Nympha a woman. What matters is that the local church met in their house. The meeting of church groups in houses is a regular feature of the New Testament (Acts 12:12; Acts 20:8; 1 Corinthians 16:19; Romans 16:5; Philemon 1:2; possibly Acts 16:40). Large houses may well have been able to take the whole congregation in a city and in larger cities there would be a number of congregations meeting in different places united under a joint ministry. There were, of course, no known church buildings. It was because they met in houses that they did not so quickly come to the notice of the authorities as an unauthorised sect (that and the fact that they were seen as of the Jewish religion).