It may help to review the proper role of the Church. In my reading of your comments, it appears that you think the Church should have as it's primary function some important social purpose, i.e. trying to make everyone "feel good" by meeting their physical and emotional needs. This is understandable since ALL of the large, mainline churches have adopted this "social gospel" focus. While Christians are indeed to show compassion to their fellow man, as motivated by the Gospel, which we do indeed do, this is not the purpose of the church. The PRIMARY function of the church is meeting the SPIRITUAL needs of mankind. The church has a simple teaching and baptizing mission, given by the Lord Jesus Christ Himself just before He ascended into heaven:
Matthew 28
18 And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth.
19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world. Amen.
Matthew 28
18 And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth.
19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world. Amen.
John 17
3And this is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent.
Acts 4
12Nor is there salvation in any other, for there is no other name under heaven given among men by which we must be saved."
We should disavow the position that the church as a body is to promote social and political causes and opinions of men. The individual Christian will indeed show the fruits of faith by his concern for social and political causes wherever they present themselves. Our right of existence as a church, however, is limited by our readiness to say with St. Paul that we are "... determined not to know any thing among you, save Jesus Christ, and him crucified." (1 Corinthians 2:2)
1 Peter 2
9But you are a chosen generation, a royal priesthood, a holy nation, His own special people, that you may proclaim the praises of Him who called you out of darkness into His marvelous light;
Matthew 5
Believers Are Salt and Light
13 "You are the salt of the earth; but if the salt loses its flavor, how shall it be seasoned? It is then good for nothing but to be thrown out and trampled underfoot by men.
14"You are the light of the world. A city that is set on a hill cannot be hidden. 15Nor do they light a lamp and put it under a basket, but on a lampstand, and it gives light to all who are in the house. 16Let your light so shine before men, that they may see your good works and glorify your Father in heaven.
Again, the focus of the Church, according to the above clear passages, is to attend to the SPIRITUAL needs of the world. Out of Gospel-motivated compassion for our fellow man, individual and/or groups of Christians may join together to meet the social and/or physical needs of suffering peoples, but that is NOT the purpose of the Church.
The joint prayer service was indeed a worship service. I suggest you read the "Faithfulness and Judging" section of my post 95 to help you understand the Scriptural reasons why God wants us to only worship/pray/commune with people who share the same confession of faith. If you do not care to wade through that, please at least consider the following passages by way of explanation:
1 Corinthians 1
Sectarianism Is Sin
10 Now I plead with you, brethren, by the name of our Lord Jesus Christ, that you all speak the same thing, and that there be no divisions among you, but that you be perfectly joined together in the same mind and in the same judgment.
2 Corinthians 6
14Do not be unequally yoked together with unbelievers. For what fellowship has righteousness with lawlessness? And what communion has light with darkness? 15And what accord has Christ with Belial? Or what part has a believer with an unbeliever? ... 17Therefore Come out from among them And be separate, says the Lord...
Ephesians 5
6Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience. 7Therefore do not be partakers with them.
2 John 1
10If anyone comes to you and does not bring this doctrine, do not receive him into your house nor greet him; 11for he who greets him shares in his evil deeds.
Romans 16
Avoid Divisive Persons
17 Now I urge you, brethren, note those who cause divisions and offenses, contrary to the doctrine which you learned, and avoid them. 18For those who are such do not serve our Lord Jesus Christ, but their own belly, and by smooth words and flattering speech deceive the hearts of the simple.