The attributes of the 144,000 in Revelation 7 and 14 are found in prophecies of Israel, indicating that a humbled remnant of Israel will turn to God.
God employs a winnowing process in selecting those who will enter the Millennium. The process includes punishment for Israel's failure to serve as priests.
During Jacob's Trouble, a confederacy of gentile peoples (particularly the offspring of Ishmael and Esau) will destroy the nations of modern-day Israel.
Keeping the Feast of Tabernacles includes temporary dwellings, rejoicing before God, and learning to fear God and faithfully keep His law.
Following our passions only applies if we invest the career capital to perfect our craft, honing our skills so that other people will pay for what we have to offer.