We are called to be generous people because God is a generous God. Generosity requires sacrifice to give more than is expected.
"He predestined us to be adopted as sons through Jesus Christ for himself, according to the good pleasure of his will, to the praise of his glorious grace that he lavished on us in the Beloved One. In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace that he richly poured out on us with all wisdom and understanding." (Ephesians 1:5–8)
It is God’s will to pour out his grace upon us generously. God’s generosity towards humankind results in praise for his glorious grace.
If God is generous towards us, the pattern is that we should be generous in his likeness. During Lent, we should intentionally make an effort to be generous to each other–neighbors, friends, and especially each other in the church. When we are generous towards each other, it reminds us of God’s generosity through Christ, and we give thanks to God.
Lent is a time of sacrifice that grows us spiritually so we become more like God. So generously giving to God is a natural thing to do at this time.