I notice at my church they preach tithing at the collection, but I think it is wrong to bind tithing on Christians. I don't want to stir up trouble, but if they teach and dwell on it that we should do it, I'll say something. Right now all the congregation thinks it is mandated, but no where do we see followers of Jesus exhorted to tithe in the NT or for the NT saints. We are encouraged to give generously. We are free to give as we purpose in our heart; we can give 100%, 50%, 20%, or 10% or less, but binding tithe on believers is like imposing the law and severing us from Christ.
If pastors preach tithing, then they should be demanded a Levitical, Festival, and Poor tithe...3 types of tithes, not one.
In the N.T., Paul could very easily have reminded Christians to tithe in 2 Cor 9. Instead, he wrote:
Each of you should give what you have decided in your heart to give, not reluctantly or under compulsion, for God loves a cheerful giver. -2 Cor 9:7.
Give as you can, give generously as circumstances allow, and give as you feel led.
If a church is mandating it, I'd recommend finding a different church.