There is a lot of preachers that like to preach give to the Church so they can live a comfortable, prosperous life, especially television evangelists.
Get in to contact with a preacher on television for help, and they most likely will respond asking for money, as if that is their concern more than the problem, or question you pose to them.
Their main concern seems to be money for themselves, before work of the ministry, with some being millionaires, and driving nice cars, and living in nice houses, and trying to convince the congregation they deserve that money, and prosperity, for they preach the Gospel.
But Paul said the preacher is not to be in the ministry for the money, and if they preach that God blesses with money for their wants withdraw yourselves from them, having food, and clothing be content, and God wants equality among the saints, so the preacher does not get blessed any more than any saint.
And the early Church sold all their possessions that was not a necessity, and laid the money at the apostles feet, which they did not use it for personal use, but distributed the money to the poor.
But many preachers use the money that is given for their own personal use, which is for the people so their needs are met, and some preachers, like again television evangelists, are living lavishly, even doling that money out to their children to live lavishly too, and neglecting the purpose of what the money is to be used for.
And this is strange concerning Africa, that there are preachers that are millionaires, taking advantage of the people, but you would think that in such a country that does not prosper like America, that they would have some kind of compassion upon the people, but people are the same all over the world, and the love of money the root of all evil, for it neglects the poor and needy.
It is true that many preachers take advantage of the congregation to cause money to flow in to their Church, so they can live lavishly, or at least have a very comfortable good lifestyle, all at the expense of the people, even taking advantage of old people, and the widows, the same as the Pharisees were doing.
So they probably know they do not have any backing for the preaching of tithes, but they do it anyway for it keeps the money flowing to them to prosper them.