Is a non-WELS person (another Lutheran synod, Catholic, Baptist, etc.) permitted to solo during the funeral service of a WELS member in a WELS church?
Singers and musicians—those who serve as worship leaders in regular or special worship services in our churches—do need to be of our fellowship.
The Bible encourages us to work together with those who have a common faith and to work together to promote the truth (3 John 8). At the same time God, through the Bible, tells us to separate from and not join in fellowship activities like worship with those who are not one in faith with us (Romans 16:17; Titus 3:10; 2 John 10-11).
When people belong to a church, their membership acknowledges acceptance of that church’s beliefs. It is the comparison of the church’s beliefs with the Bible, not an examination of the individual’s heart, that leads to a determination of whether or not there can be the enjoyment of fellowship activities like worship.
When I answer questions like this, I like to point out that we are talking about the difference between visible churches and the invisible church, the Holy Christian Church. WELS and the churches you listed are visible churches. If a person from one of the visible churches you listed is not able to sing a song in one of our churches, we are not saying the person is not a Christian, nor are we pretending to read what is in the person’s heart. We are happy when a person’s sincere confession of Christian faith identifies him or her as a member of the Holy Christian Church, the invisible church. But only God knows who belongs to that Church; you and I operate in the realm of visible churches. So, while we may have a common membership in the Holy Christian Church with other Christians, their membership in a visible church outside our fellowship prevents us from doing the things we might like—like singing at a funeral service.
If you would like to read more about our biblical fellowship practices, this link will take you to the appropriate section of This We Believe, a statement of belief of our church body. And, finally, please do speak to one of our pastors if you have other questions related to the one you submitted.