I saw a video recently in which a pastor said "Your first fruit is for me".

Your pastors taught you that prosperity (financial freedom) is from your God.
Your pastors taught you that you need to give to their God before their God can bless you.

If we've all agreed that financial freedom is a blessing from your God. Then, you are in soup for hoping you'd be blessed by paying tithes, offerings, seed and first fruits.

For your bible says:
"You will perish with your money," replied Peter, "because you have imagined that you can obtain God's blessings with money! -Acts 8:20

In the rule of business, you don't eat your first fruit. You save it and plant it again.