A Desire becomes a Hope when we discover a reason for its expectation. The strength of the reason, determines the strength of the corresponding expectation. The Desire is now both a Hope and a Desire. It becomes both, like the way something can be both red and big at the same time.
In the same way that a Desire is enhanced by Hope, Desire and Hope are both enhanced by Faith.
Faith is the reality of things hoped for, the evidence of things not seen. Hebrews 11:1
A Hope becomes a reality when God conveys its reality to our heart. He changes the expectation into a reality. The desire and its hope are given reality through the agency of Faith, but they remain what they are. Just as Desire is not changed into Hope, Hope is not changed into Faith.
Jesus is the object of our Hope, and we patiently wait for Him in Faith. He is the Hope for which we are in Faith. He is real whether we know it or not. He becomes a reality to us when we know that He is a reality, and we know He is a reality by the Faith in our hearts. He does not change – we are the ones who change – when we receive the impartation of His reality from God into our hearts. We receive the reality of something that already is, and it becomes our reality. This impartation, this ‘hearing’ from God, is the evidence of things not seen (to the world).
Faith comes by hearing, and hearing by the word of God (Christ). Romans 10:17
Desire gives us focus, Hope gives us expectation, and Faith gives us reality. The Desire is the purpose and Faith is the means.
Hope is still a Hope, even when it becomes a reality.
See also: What is Bible Hope?