The bible never actually mandates giving 10% of your money to anything, much less the church, which didn't exist. That said, it does say a lot about wealth and how it should be used.

" From everyone to whom much has been given, much will be required; and from one to whom much has been entrusted, even more will be demanded."

"...The rust of your wealth will be used as evidence against you."

In fact, a very central theme throughout the Bible is along the lines of, "I told you guys to take care of the poor and needy. You didn't do that. I'm pretty pissed about it, FYI. So, I'm going to tell you again. Take care of the poor and needy. --Sincerely, God".

Personally, I think people should be generous with their money. I think Christians, if they believe anything Jesus said, have an obligation to be generous. Our family gives money to our church but our church is highly mission centered and we do what we can to take care of those in our community who have needs. It's good to be able to help people but it's also very sobering because you find out that the needs are enormous.

The fact that a lot of churches have a money furnace in the basement and don't contribute anything meaningful to the world has earned Christianity some well deserved criticism. But not all churches are like that.

You should be charitable to the extent you are able. No more, no less. And money, time, and talent are all valid ways to do that.