I believe in seed faith, but the harvest comes from the particular type of seed sown. If I sow seeds of kindness and gentleness, then I will reap a harvest of kindness and gentleness from others. If I sow a seed of helping a neighbour, then I will reap assistance from neighbours when I need it. In the same way, when the Holy Spirit asks me to give a financial donation, then when I need financial help, then it will come to me. That is in accordance with the Scripture that says that we reap what we sow.
I am a Presbyterian. That means that I have to keep a careful watch on my wallet to ensure that the moth doesn't fly out!
But in a conference, the Holy Spirit asked me to contribute my lunch money to the offering. It was only $10, but it was my lunch money, and so I gave, but wondered how I was going to have any lunch. I would probably have to get all spiritual and fast!
What happened was that I was offered two lunches. When I got to work I found that my salary had increased $12,000 per year, and a month later, as a speaker in another conference, my share of the love offering for speakers was around $300! So, I sowed $10, and reaped pressed down and running over!
But I don't believe a preacher manipulating people into giving to his ministry and his personal wealth by promising prosperity through it. The principle that Jesus taught was that we give generously for sure, but not to expect any kind of repayment. Actually it is more blessed to give to someone who can never pay us back. But if God decides to reward us by allowing us to reap what we sowed, then that is from His sovereign will, rather than God being a pokey machine in which we put in our dollars and expecting a jackpot later on! The trouble with prosperity preachers who manipulate good people out of their money with the promise of prosperity, they are the only ones who receive the jackpot!! Just like the guys at the top of the pyramid of pyramid marketing, while the ones down at the bottom get nothing for their investment.