A biblical perspective
In reaction to God's grace
God has shown His great love for sinful and unworthy people like us, in life, death and resurrection of the Lord Jesus. Having received such undeserved generosity we should be motivated to give generously in response. We are to be like God - ready, not reluctant givers, for God loves a cheerful giver.
In recognition of God's gifts
Giving is not limited to financial giving. God has given us all we need to give generously, but not all of us can give financially. God wants us to be generous not just with our money but with our time, energy, skills, property and homes. If we have received God's abundant grace then we all have something to give generously. Sometimes these other things are harder to give than money.
In response to needs and priorities
Paul encourages the Corinthian Christians to give generously to a collection for other Christians in great poverty. God's priorities are that His people should come first in our giving: those who teach the word of God (1 Tim 5:17), those in need in our church (James 1:27, 1 Tim 5:8) and those in need in other churches (2 Cor. 8-9). The needs may be local (eg the ministry at St Andrew's) or further afield (in the UK or abroad).