II. Sing them exactly as they are printed here, without altering or mending them at all; and if you have learned to sing them otherwise, unlearn it as soon as you can. - John Wesley
Western Christians find ourselves in a highly individualized society. I've grown to respect the scholarship of Andrew Fellows, a director of English L'Abri, who calls this narcissistic preoccupation, "the worldview of self."
All this has brought us is an increasing disconnection.
I would imagine this is what has happened to the Church. Pews are empty, attendance is dropping, and churches are trying to adapt, but it's not easy fighting such a pervasive force. When we have lost the art of face-to-face communication, church seems old-fashioned, obsolete and, to a large extent, contrived.
Corporate worship has grown more individualized as well, and John Wesley's second directive gives us some clear insight that can help us maintain our identity in corporate worship.
The Church's gathered worship, all the way back to the Bible, has been a group effort; an "us and God" conversation. But the tide has turned more recently to an individual venture, a completely vertical, "me and God" conversation. For instance, most of us who have been around church gatherings for a long time have probably been repeated admonished to make our corporate worship a private affair.
There's obviously nothing wrong with private worship, but it's just that: private. If we're worshiping as a community instead of individuals, our voices are unified; they form a collective and diverse, but cohesive whole. Many gifts, but one unifying Spirit. What a powerful and glorious visible manifestation of Christ's body!
On a more practical level, it can also prevent a gathered worship exercise from being or becoming too performance-driven. If our congregational singing follows a prescribed text and tone, nobody is "stealing the show," but our voices are as unified as possible.
So if we all learn to sing the same song - just as we share the same Spirit and confess the same faith, we will be practicing and rehearsing for our participation in Christ's Kingdom and ultimately in the great choir offering up a great collective voice, singing "Holy, holy, holy, is the Lord God Almighty."
So keep practicing until the time comes for us to cast our crowns before our King, lost in wonder, love and praise.