Sukkot is derived from the Hebrew word sukkah (Strong's #H5521) which means a temporary dwelling such as a booth or tabernacle. It is a shortened reference to the Biblical fall festival period commonly called, in the KJV Bible, the Feast of Tabernacles (Leviticus 23:34, Deuteronomy 16:13, 16, etc.). It is also referenced as the Feast of Ingathering, Harvest or Booths (Exodus 23:16, 34:22, Leviticus 23:42).
The Feast of Tabernacles (Booths), the sixth of God's seven annual festival periods, is celebrated for seven days in the fall (Tishri 15 to 21 which occurs during September - October). The major passages related to this celebration are in Leviticus 23, Deuteronomy 16, Zechariah 14 and John 7.
Old Testament purpose
God commanded ancient Israel to celebrate the Feast of Booths by constructing and living in temporary housing built out of tree branches, boughs and other naturally occurring materials (Leviticus 23:39 - 40, 42).
The Feast of Tabernacles was a harvest time festival of thanksgiving to rejoice over God's abundant blessings. It also served to remind the Israelites that God lovingly took care of them when they sojourned the wilderness after leaving Egyptian bondage (Leviticus 23:43).
Special Psalms were often sung during this time, especially by pilgrims on their way to Jerusalem. These included Psalms 113 to 118, known as the Hallel (Praise God) Psalms, and 120 to 134, which are labeled the songs of ascent.
New Covenant symbolism
This festival, in ancient Israel, was considered the greatest of them all. It was a time of great joy and thanksgiving before the Lord for his abundance blessings. A good time was virtually guaranteed since each person was to save a tithe of their increase to spend solely on keeping the Feast of Tabernacles (Deuteronomy 14:22 - 27)!
The Feast of Booths is symbolic of the upcoming millennial reign of Jesus on the earth. He and all the resurrected Christians (Revelation 20:4 - 6) will insure, from their headquarters in Jerusalem, that peace and prosperity come to all (see Isaiah 2, 11, Micah 4). God will also set his hand to teaching the entire world his ways. The fruit of his efforts will be a 1,000-year long great "harvest" of people who will receive salvation and enter into eternal life.
A temporary sojourn
As stated previously, one of the central concepts of the Feast of Tabernacles is to live, for a short time, in a place that is built to be temporary. The Apostle John wrote that Jesus, who was God, was willing to live in the temporary "tabernacle" of human flesh in order to die for our sins (John 1:1 - 3, 14, 29).
The Apostle Paul wrote that those who receive the Holy Spirit become a temple or tabernacle for God to dwell in (1Corinthians 3:16 - 17, 2Corinthians 6:16). Our flesh, however, was not meant to last a long time. Christians yearn for the time when their "fleshy tabernacle" is gone and they are given an indestructible spirit body in the resurrection (2Corinthians 5:1 - 4, 1Corinthians 15:48 - 54).
Should we keep it?
The Biblical record shows that the keeping of the Feast of Tabernacles was retained during New Testament times. In 29 A.D. Jesus celebrated it and came close to being arrested in Jerusalem (John 7). The Apostle Paul cut short his stay in Ephesus so that he could arrive in Jerusalem in time to observe the festival (Acts 18:19 - 21).
Zechariah 14's prophecy is set during the yet future time when Christ returns to establish God's Kingdom on the earth. Ruling from Jerusalem, he will command ALL people keep his Holy Days every year.
And it shall come to pass that everyone who is left of all the nations which came up against Jerusalem shall even go up from year to year to worship the King, the Lord of hosts, and to keep the Feast of Tabernacles (Zechariah 14:16).
Anyone who flatly refuses to observe the Feast of Tabernacles (Booths) will be supernaturally punished with no rain and drought conditions (Zechariah 14:17 - 19)! God's festivals should be kept today, as they were never abolished in the New Covenant!