Consider communicating a promise to your donor. Not just any promise, but one that your donor values, because people give to what they value.
A text can express two kinds of values: concrete and abstract values. The former refers to tangible things like love of country, something you can touch. The latter refers to intangible things like excellence, prosperity, honour, justice, the latter being the stronger motivator to action. The point here is to know what the donor values and to align your appeal accordingly, paying particular attention to the abstract values.
When asking for support, ask yourself what return on investment am I promising the donor? Take education and scholarships, for example. What's the donor's prime motivator: helping a student excel or producing talent for the workforce? With a clear sense of which message will resonate more, you can communicate more effectively with your donor.