The reason many believers are not significant givers is because they have never been significant receivers. They have never fully accepted God’s extraordinary flow of unconditional love that constantly pours over them. Until you fully receive God’s unconditional love, you will never be passionately motivated to love Him back.
Freedom from the law of Old Testament taxation is not freedom to give less. It is freedom to give in the ways and the amounts that properly reflect our deep, abiding love and gratitude for our Father and His Kingdom. It should reflect our desire to give to Him with the same sacrificial abandon that He gave to us when He sent His son to rescue us.