The Apostles didn't mandate tithing in the New Testament Church. However, should disciples of Jesus Christ choose to tithe 10% of their income, God has promised to open the windows of heaven and pour out blessings that will overwhelm them (Malachi 3:10).
Apostle Paul taught us that we should be cheerful givers and that we'll reap what we sow. He explained that if we sow only a little, we'll only reap a little. He wrote: "Upon the first day of the week let every one of you lay by him in store, as God hath prospered him, that there be no gatherings when I come". (1 Corinthians 16:2)