Question: Just wondering whether you can help me to understand what normally happens in a church when people are worshipping. I don't really understand why people tend to lift their hands in air. Is there any scripture to explain that or its method?
 It is referred to in the Bible in the context of repentance, prayer or worship:
Read these references, and their immediate context:
Nehemiah 8:6: an initial act of worship by a large group when Ezra was about to read the Law of the Lord; note that the physical action of lifting the hands was followed by another physical action of bowing down and worshipping the Lord with their faces to the ground.
Psalm 28:2: an individual action, accompanying a cry for mercy and help.
Psalm 63:4: an individual expression of praise to God, accompanied by singing [verse 5]
Psalm 119:48: an individual expression of acknowledgement of, commitment to and praise of the commands of God [read verses41-48]
Psalm 141:2: an individual expression of prayer [read verses 1-2]
Lamentations 2:19: an expression of rather urgent and sustained prayer in a day of terrible calamity [read verses 18-22]
Lamentations 3:41: part of an exhortation to a national expression of repentence in the context of God's judgement on the nations sins [read verses 39-45]
1Timothy 2:8: in the context of a command to pray without anger and disputing.
In each of these the lifting of hands can be understood to be a symbolic physical action expressing the reaching up of the human heart/mind/being towards God - in the three contexts of worship, prayer or repentance.
Note that only the last two of these are commands - one commanding the nation to repent, the other commands men to pray without anger or disputing; neither is saying that hands must be lifted up; all of the others are simple statements about what an individual or group actually did.
 It seems to be practised more commonly in some cultures/races than others.
Some cultures/races [and also some personalities] seem more inclined to physical expressions of inner emotions than others. Some are more conservative, or more inclined to process and express emotions in thought and word; some process and express emotions in bodily actions. That is simply the way it is. Some cultures/races also tend to communicate truth by physical action, especially group dance or mime. Such contexts lend themselves to the lifting up of hands as an expression of worship, prayer and repentance towards God.
 Pentecostal/Charismatic churches and Christians regularly lift up hands, either in the group context or individually
Until the 1960s, when the modern Charismatic movement began, it was uncommon to see people lifting hands in church in European countries and cultures. People in the Pentecostal and Charismatic movement regularly lifts hands in worship in church. There are today so many Pentecostal and Charismatic churches, lifting hands in worship, and often seen on TV programs, that the practice of lifting hands has become rather common, and has migrated into some non-Pentecostal and non-Charismatic churches. In these contexts, if it is being done biblically, it should be an physical expression of worship, prayer or repentance.
 Dangers with lifting up of hands
There are a number of dangers with the practice of lifting up of hands:
Copyright Rosemary Bardsley 2010