Why is it that Gospel and Pentecostal churches focus so much on Tithing than other denominations? Quoting Malachi 3:10.....
To the extent that they would even say an individual who doesn't pay wont make heaven?
Personally I am not against tithing but I sense something fishy about how some churches go about it.
Let's see what the bible says about it in other books of the bible....

Deuteronomy 14:22-29 Be sure to set aside a tenth of all that your fields produce each year. Eat the tithe of your grain, new wine and olive oil, and the firstborn of your herds and flocks in the presence of the LORD your God at the place he will choose as a dwelling for his Name, so that you may learn to revere the LORD your God always. But if that place is too distant and you have been blessed by the LORD your God and cannot carry your tithe (because the place where the LORD will choose to put his Name is so far away), then exchange your tithe for silver, and take the silver with you and go to the place the LORD your God will choose. Use the silver to buy whatever you like: cattle, sheep, wine or other fermented drink, or anything you wish. Then you and your household shall eat there in the presence of the LORD your God and rejoice. And do not neglect the Levites living in your towns, for they have no allotment or inheritance of their own. At the end of every three years, bring all the tithes of that year's produce and store it in your towns, so that the Levites (who have no allotment or inheritance of their own) and the foreigners, the fatherless and the widows who live in your towns may come and eat and be satisfied, and so that the LORD your God may bless you in all the work of your hands.

Whereas in the new testament Jesus Himself didn't lay so much emphasis on the issue in
Matthew 23:23 "Woe to you, teachers of the law and Pharisees, you hypocrites! You give a tenth of your spices—mint, dill and cumin. But you have neglected the more important matters of the law—justice, mercy and faithfulness. You should have practiced the latter, without neglecting the former.

2 Corinthians 9:7 Each one must give as he has decided in his heart, not reluctantly or under compulsion, for God loves a cheerful giver.

Shalom