It truly and honestly grieves me the way some pastors approach giving. It breaks my heart to see Malachi 3 twisted, perverted, and used, out of context, by pastors to manipulate and beat the sheep of their flock into forking over 10 percent of their income to avoid being cursed by God.
I have heard pastors say that the reason your car breaks down, the reason your health is failing, the reason your marriage is suffering is because you have not tithed. God, they say, will get His ten percent one way or another.
Let me ask you this – if your adopted son or daughter whom you love very much and paid a great price to go through the adoption process, gets a job but does not pay you a certain percent of their paycheck, will you curse them?
Matthew 17:24-27 (English Standard Version)
The Temple Tax
24(A) When they came to Capernaum, the collectors of(B) the two-drachma tax went up to Peter and said, “Does your teacher not pay the tax?” 25He said, “Yes.” And when he came into the house, Jesus spoke to him first, saying, (C) “What do you think, Simon? From whom do kings of the earth take toll or(D) tax? From their sons or from others?” 26And when he said, “From others,” Jesus said to him, “Then the sons are free. 27However, not to give offense to them, go to the sea and cast a hook and take the first fish that comes up, and when you open its mouth you will find a shekel.[a] Take that and give it to them for me and for yourself.”
Galatians 4:7 So you are no longer a slave, but a son, and if a son, then an heir through God.
So many things are wrong with the idea that God will curse His redeemed for not following an Old Testament prescriptive that relates specifically to the Levites. So many things are wrong with the idea that your misfortunes are due to the fact that you do not tithe. Many non-Christians enjoy great health, great financial security, and have wonderful marriages and have never gave a dime to a church or charity. Many faithful Christians who dearly love the triune God and give sacrificially of their money, time, and talents to those in need, to the local church, to charities, suffer from illness, joblessness, and failed relationships. Even so, those who give out of a cheerful heart will be blessed in ways sometimes tangible and financial and sometimes in ways not so immediate and tangible.
To say, though, that the reason a Christian suffers in this world is because they do not tithe runs the risk of making God seem like a mobster who runs a protection racket, a monster. Further, the way tithing is often taught turns the theology of giving into an act that borders on the heretical, that turns the act of joyful giving into a ‘health, wealth, and prosperity‘ scheme that encourages giving to increase oneself.
What I do not want to do is encourage Christians not to give. For some, to give ten percent, be it from the gross or the net, would be an insurmountable difficulty and would be unwise. God expects you to take care of your family. For others, ten percent would not be a difficult commitment at all, and perhaps one could give even more.
Though I could give many valid reasons why I think the tithe is not for the church, and perhaps I may do so later, the bottom is line is this: Jesus is not so much into percentages as He is into the state of our heart. What we do with our money, much like the words that come out of our mouth or end up on our blogs, reveal the state of our heart, and if you and I are honest, we all need more than a bit of grace in that area.
2 Corinthians 9:7
English Standard Version (©2001)
Each one must give as he has decided in his heart, not reluctantly or under compulsion, for God loves a cheerful giver.
Cutting to the chase, when someone beats you up with Malachi 3, go to Romans 8:1 and then read the book of Galatians with tithing in mind. As I have said before, if redeemed by the Law, give by the Law. If redeemed by Grace, then give by grace.
Remember, too, that there were three tithes in the Old Testament that equaled 23.3 percent, so if you insist on being bound to the Law, do it right. Also, since money, personal income was rarely tithed by Israel, would not bringing your livestock and produce to church as an offering be an interesting spectacle?
As I was looking for some media to ‘spice up’ this post, I found the following video. While I did not have this man in mind, he is only turning the volume to 11 where your typical mega-church pastor may only leave the volume at 6, metaphorically speaking. Watch and weep over this video by the appropriately named Creflo Dollar:
The Book of Ron 
I think you hit on it when you said it makes God look like a mobster. Now realize that the tithing racket is a form of organized crime, it just isn’t illegal activity to guilt someone and extort them through the fear of excommunication or social ostracization.