‘For which reason receive you one another, even as Christ also received you, to the glory of God.'
The thought is the same as in Romans 14:3, that Jewish Christians and Gentile Christians might receive each other because God, or in this case God's Messiah, has received them. And this to the glory of God. This would serve to confirm that in Romans 14:3 Jew/Gentile distinctions were in mind. The change from ‘God' to ‘the Messiah' was necessary in order to connect with what follows where Paul will demonstrate that the Messiah came on behalf of both. It is a continuing plea for essential unity.