Beatitudes come from the Latin word beatus, meaning "blessed" or "happy." In Hebrew, it is baruch, which fundamentally means "to kneel" or "to bend the knee."
In the ancient Semitic worldview, a blessing was a tangible act. When God or an individual bestows a blessing, it means they are bending the knee to honour someone, and releasing tangible favour, authority, and prosperity into their life. Because the root word means to kneel, baruch is also used to express worship, honour, and praise to a higher power. Another Hebrew word, ashrey, is also translated as "blessed" (or "happy"). It signifies a state of being content, aligned with God's Will, and living "the good life."
Being "blessed" in Jesus' sermon does not necessarily mean feeling happy, but rather, recognising what is truly good in a person's life, and why. Each of the beatitudes cites an outcome that arises from a condition. How wonderful it is when a person experiences all the blessings that arise: The poor in spirit are blessed with the Kingdom of Heaven; the gentle will inherit the earth; the mourning are comforted; and the hungry are filled. Ultimately, it is a dependence on God to care and provide, and to live in His ways. Then, God's blessings are the reward.
It is not easy, and God knows. He just asks us to trust Him and strive to live His ways. And that, the Saints have done to reach the ultimate reward - eternality with God.
All you holy men and women, pray for us.