These teachings that have been popular in the faith movement for years is the equivalent of "giving to get". Many of the prosperity preachers are praciticing what they are preaching, because they are living like kings in this world, and to them financial prosperity is the equivalent of spirituality.
Many of these teachers are teaching that not only will God reward you with financial blessings if you sow your seed into their ministry, but He will bless you with whatever it is that you are believing for. This is the equivalent of the selling of indulgences that took place in the Catholic Church during the days of Luther.
The Word of God does teach the principle of sowing and reaping, but many of these teachers are not teaching the whole word on the subject.
Christians should follow the instructions in the Word and flee from these teachers.
"If any man teach otherwise, and consent not to wholesome words, even the words of our Lord Jesus Christ, and to the doctrine which is according to godliness; He is proud, knowing nothing, but doting about questions and strifes of words, whereof cometh envy, strife, railings, evil surmisings, Perverse disputings of men of corrupt minds, and destitute of the truth, supposing that gain is godliness: from such withdraw thyself. But godliness with contentment is great gain. For we brought nothing into this world, and it is certain we can carry nothing out. And having food and raiment let us be therewith content. But they that will be rich fall into temptation and a snare, and into many foolish and hurtful lusts, which drown men in destruction and perdition. For the love of money is the root of all evil: which while some coveted after, they have erred from the faith, and pierced themselves through with many sorrows." (1 Timothy 6:3-10).