As followers of Jesus we don't give financially in an effort to win God’s approval, favor, or love. That has already been lavished upon us freely through the life, death and resurrection of our Great God & Savior Jesus Christ (See Romans 5:8 and 1 John 4:10). Rather, we give as a response to the gospel. We give as an act of worship. We give because God first gave (See John 3:16)!
Simply put, giving financially toward the forward progress of the gospel of Jesus is an act of worship. At Emmaus Church at least 10% of every offering received is devoted to outside church planting.