Giving financially is Biblical and an act of worship to God. Throughout the pages of the Old Testament, you see God's people worship through giving the tithe (10% of their income) back to God to recognize His provision. They also brought offerings, which are freely given and in addition to the tithe. However, Jesus fulfilled the requirements of the law (specific religious duties) and spoke how God desires a generous heart, not a fixed religious amount. While 10 percent is fair to everyone regardless of income--God is worthy of everything!
As believers, we are learning to live open-handed. Having an open hand means that what is in the hand is not ours...and therefore we do not hold on to it too tightly. Having an open hand also means that God can both take from the hand and place into the hand as He sees fit. As we look to Jesus to provide everything we need, giving generously becomes easier and having an open hand becomes more of a joy. As a result, we do not give expecting God will place something else in our hand, we give because He is generous with us. We give generously because it reflects His character. We give because what is in our hand, no matter how valuable it is, pales in comparison to Jesus.
Please pray and give as God leads, not out of what you think is right, or from fear of punishment, or from fear of going without. God is generous with us and we should give generously to Him from a thankful heart. We are free to worship God with the first and the best of what He has graciously provided us, not from our leftovers. Because giving to God is worship, it should be given freely, generously, and even sacrificially.