They might mistake and think it is not good.
No need to explain to non-believers.
For new believers, through Bible study you can tell them the tithe is the law in Old Testament, which is to support Levites the servants of God. In New testament, there’s no the law of tithe any more. But still the Church need the donation from the believers to support the workers in the Church and the mission development. They can donate as their will. Maybe it’s difficult for the new believers to donate, but later when they know God’s love more and the meaning of Church, they will be very happy to donate.
Preach the word of God boldly…Elijah asked widow boldly “give me first cake”
God gives man everything, everything, include ourselves belongs to God. God ask us to give tithe, even this is for our goodness. For example, I love my baby, give him everything, but I ask my baby give a piece of apple( my baby likes apple a lot). I actually don’t want to eat that. But I want to train him to love back and experience the joy of love.