How much should I give?
Some today argue against the tithe, or 10% of gross income, but Abraham and Jacob gave it before Moses’ law (Gen 14:18-20; 28:22). While a tithe is not specifically required in the N.T., it is the example the O.T. gives, just like the details for other N.T. duties e.g. child discipline. A tithe is what we owe God, and giving above that is an offering, thus tithes and offerings (Mal 3:8). If you grasp what God has done for you (II Cor 8:9; 9:15) and His promised blessings for liberal giving (Pr 11:24-26; II Cor 9:6), you should want to give very generously and cheerfully.
If you think of the previous paragraph as giving to your church for its laborers and needs, then you also have charity toward the poor to consider. But God mercifully and wisely only holds you responsible for poor in your family, for poor in your church, for those of the same faith and practice in other churches dealing with broad acts of God and destitute, and desperate needs he puts directly in your path in your ordinary business, like the Good Samaritan (Luke 10:25-37).
Much more about tithing in the Bible: Should Christians Tithe?
More about Christian charity: Haiti Earthquake.
More about Christian charity: What About Tsunami Relief?