"What would Jesus sing?"
Much of contemporary worship sings to Jesus. But Jesus would sing to the Father. In Matthew 11 he praises the Father. In John 12 Jesus says, "Father, glorify your name!" In John 8 Jesus says, "If I glorify myself, my glory means nothing."
So why do we sing so many songs to Jesus? I don't mean to say we should throw them out, but can we balance it with some songs that Jesus would sing? Songs that are directed to the Father, or to the Holy Spirit?
"What would Paul plan?"
Paul is great at telling the whole story. Look at Ephesians 1:
"3 Praise be to the God and Father of our Lord Jesus Christ, who has blessed us in the heavenly realms with every spiritual blessing in Christ. 4 For he chose us in him before the creation of the world to be holy and blameless in his sight. In love 5 he predestined us for adoption to sonship through Jesus Christ, in accordance with his pleasure and will— 6 to the praise of his glorious grace, which he has freely given us in the One he loves. 7 In him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of God’s grace 8 that he lavished on us. With all wisdom and understanding, 9 he made known to us the mystery of his will according to his good pleasure, which he purposed in Christ, 10 to be put into effect when the times reach their fulfillment—to bring unity to all things in heaven and on earth under Christ."
(copied from BibleGateway.com)
Whoa! He talks about grace, love, redemption, forgiveness, mystery, Christ, Christ's second coming, eternity. Paul puts in so many elements of God's story here, and we should try to do the same in planning worship services. We should tell as much of God's story as we can, as often as we can.
Maybe picking a single theme for a service isn't such a good idea, if it means neglecting the vastness of God.