3. GOD DOES NOT FELLOWSHIP THOSE PRACTICING FALSE RELIGION. This would include any religion besides New Testament Christianity. God doesn't have spiritual fellowship with those in man-made religions (e.g., Buddhism, Islam, etc.), but He also doesn't have fellowship with those in man-made churches (e.g., Lutheran, Methodist, Catholic, etc.)! God wants these people to be saved, but Jesus said it is the truth that sets one free (cf. John 8:32); not merely part of the truth, which is what man-made churches offer. Denominations have a similarity to the true church Jesus built, but they are not the true church and not in fellowship with God!
Stephen, that sounds awfully harsh! Perhaps, but don't take the issue up with me, take it up with the one who drew these lines of fellowship--God! As we have already established, God has fellowship with those who walk in the light. To walk in the light one must obey the gospel and live faithfully according to the New Testament. Do denominations teach the truth of God's word when it comes to obeying the gospel and living faithfully? Typically, no. It is rare to find any man-made church that even affirms a person must be baptized to have their sins washed away, yet the Bible plainly teaches such (cf. Acts 2:38; 22:16; Mark 16:16). Friends, how can any person or denomination--no matter how much good they do--be in fellowship with God when they don't teach or comply with His plan of salvation found in the New Testament? God is disgusted by what He sees in the vast majority of the religious world today; He does not approve of the departures from His word. He does not fellowship those who practice false religion; they are under His curse! As Paul wrote in Galatians 1:8 - "But even if we, or an angel from heaven, preach any other gospel to you than what we have preached to you, let him be accursed." No matter how sweet or kind in disposition one may be, if he has altered the truth of God's word in some way (by adding or subtracting), he is under God's condemnation! Such people are in sin and need to repent and submit to God's will.
Just being religious isn't good enough, one must be religious in the right way--God's way! Just because a person is likeable and may attend a church somewhere does not mean God is pleased with him or in fellowship with him. There were 3000 devout religious people on Pentecost who realized they needed to repent and be immersed for the forgiveness of their sins. They were religious but not right with God! Such describes many in our culture. We should do our best to reach out to those who are in man-made churches/religions. We need to love them enough to teach them, though we cannot approve or share in their errors.