Opposition to tithing is based almost exclusively on the argument that we are no longer bound by the law. I'm only pointing out that Abraham, who was not under the law, tithed to Melchizidek (a type of Christ).
If one is looking for guidance as to what portion of his increase is suitable to give to the church, we can look to Abraham as well as the law.
If one does not think it's mandatory, but out of one's heart, that's fine.
Jesus himself thought ten percent was just fine.
Regarding Joses, by definition his gift of 100% of the proceeds from the sale of a piece of land was not a tithe, but an offering.
The Apostle Paul, a pharisee of the pharisees would have taught the church to tithe if it was obligatory yet he did not. In Acts 15 with the keeping of the law controversy tithing was not one of the outcomes to keep. No where do we see the church collect the "official" tithe (all the 10th belonging to the Levites). I think if christians want to give 10, 20, 30 percent they can if they so choose but its not law to do so. Also the church took up collections for the saints whom were financially struggling and one of the reasons for this administration of the collection was "for the poor".
2 Cor 9:9 (As it is written, He hath dispersed abroad;
he hath given to the poor: his righteousness remaineth for ever.
10 Now he that ministereth seed to the sower both minister bread for your food, and multiply your seed sown, and increase the fruits of your righteousness
11 Being enriched in every thing to all bountifulness, which causeth through us thanksgiving to God.
12 For the administration of this service not only supplieth the want of the saints, but is abundant also by many thanksgivings unto God;
I think also the church has the authority to ask the members to support it financially and whatever the needs of the church happen to be. That's one reason I think churches ought to be careful not to waste money. The stone cold reality is things today cost money, bottom line.
Darren