Okay, okay, I know "cruciality" is not a word, but I made it up because I think it should be a word :) Growing up in the church, I have actually been surprised at how many people I have met that do not tithe. However, tithing is one of the ONLY instructions given to us in Scripture that is tied with a PROMISE - Malachi 3:10 (New International Version) "Bring the whole tithe into the storehouse, that there may be food in my house. Test me in this," says the LORD Almighty, "and see if I will not throw open the floodgates of heaven and pour out so much blessing that you will not have room enough for it."
Many people believe that because tithing was an instruction given by God under the old covenant, that we no longer need to do it today. However, tithing was a regular New Testament practice. Without getting into all of the theological arguments for this case, I just want to encourage anyone reading this to really pray and search your heart about this issue. Most of the people I know who have financial problems are in trouble because of one or both of these reasons: 1) They have gotten into too much debt and/or 2) They are not honoring God through tithing. I personally believe both of these are sinful behaviors.
Getting into too much debt (crown ministries distinguishes between good debt - i.e. college loans, etc.- and bad debt - i.e. credit cards for purchases we don't really need) means that we are "borrowing" money from a company when we do not have (and many times, do not plan to have) the money to pay it back on time. Romans 13:7 says "Give everyone what you owe him: If you owe taxes, pay taxes; if revenue, then revenue; if respect, then respect; if honor, then honor." Not tithing means that we are holding onto our money as if it was our own (when it is all God's money), and we are not respecting or honoring him by choosing to pay our cable bill instead of tithing.
I have heard many stories of people who say "I can't pay my tithe! I don't have enough money!" yet turn around and pay bills for a new flat screen television, a cable bill, a brand new car payment, a designer purse, etc... These items are not "needs"; they are "wants" and we have confused the two terms until we have convinced ourselves that we truly do not have money left to honor God. However, when we honor God FIRST by paying our tithe before anything else, He will always provide for our needs. I have never, ever known anyone who is tithing to not have food on their table or to be homeless.
If you are struggling financially today, I encourage you, I plead with you, to test God and see if He will not bless your desire to honor Him. Give to him first, before going shopping, before paying your cell phone bill. Ask Him to help you prioritize what your true needs are so that you can put Him back in first place in your life. Because if you are not tithing, I would really encourage you to examine if He really is first in your life. Do you trust him enough to try it?
This is an excellent article on the topic of tithing while you are in debt: http://www.crown.org/LIBRARY/ViewArticle.aspx?ArticleId=574