"Blessed are the merciful for they will be shown mercy." Matthew 5:7
Unless you have been offended you can't show mercy. So the merciful are firstly people who have been hurt by another and have extended forgiveness to that person.
Esau was tricked by his brother Jacob in a permanent and irrevocable fashion. In Genesis 27:36 Esau says, "He has deceived me these two times: He took my birth right, and now he's taken my blessing!" and later in v.41 it is recorded that Esau held a grudge against Jacob and had decided to kill him. Yet many years later when the two brothers meet it is Esau who runs to meet Jacob and embraces him, throwing his arms around his neck and kissing him (Genesis 33:4). Esau came to the place where he could forgive his brother even while he still lived with the consequences of Jacob's actions.
When forgiving others it is helpful to bear in mind that no matter how badly I have been hurt by someone else it is still not as great as my offences against a holy God. God's holiness is so boundless and his forgiveness to me is so immense that other people's offences against me are actually minor in comparison.
Another helpful thought is to remember Jesus words about the soldiers who crucified him, "Father, forgive them, for they do not know what they are doing" (Luke 23:34). Often those who hurt us have no idea that they have done so.
If we want God's blessing in our lives we need to adopt a forgiving attitude to others.