Why do we worship God?

"Worship the Lord with gladness; come before Him with joyful songs ... give thanks to Him and praise His name. For the Lord is good and His love endures for ever" (Psalm 100: 2, 4-5)

How should we worship God?

"Yet a time is coming and has now come when the true worshippers will worship the Father in spirit and truth, for they are a kind of worshipper the Father seeks. God is spirit and his worshippers must worship in spirit and in truth" (John 4: 23-24)

Why do we lift our hands?

"I will praise you as long as I live, and in your name I will lift up my hands"  (Psalm 63:4)
"Lift your hands in the sanctuary and praise the Lord" (Psalm 134:2)
"I want men everywhere to lift up holy hands in prayer" (1 Tim 2:8)

Why do we clap our hands?

"Clap your hands, all you nations, shout to God with cries of joy" (Psalm 47:1)

Why are musical instruments part of the worship service?

"Praise Him with the sounding of the trumpet, praise Him with the harp and lyre, praise Him with tambourine and dancing, praise Him with the strings and flute, praise Him with the clash of cymbals, praise Him with resounding cymbals." (Psalm 150:3-5)

Why does the whole church pray at once for specific needs?

"On their release, Peter and John went back to their own people and reported all that the chief priests and elders had said to them. When they heard this, they raised their voices together in prayer to God" (Acts 4:23-24a)
"So Peter was kept in prison, but the church was earnestly praying for him. Suddenly an angel of the Lord appeared ... "quick, get up!" he said, and the chains fell off Peter's wrists... he went to the house... where many people had gathered and were praying." (Acts 12:5,7,12)