There are several things to realize about the Old Testament harvests and feasts.
The three harvests (Exodus 23:14-17) parallel the Crucifixion/Resurrection, Pentecost/The Church, and Christ’s Return (1 Corinthians 15:23-24).
The seven feasts of these harvests (Leviticus 23) correspond to the Church’s liturgical seasons: Advent, Christmas, Ordinary, Lent, Triduum, Easter, Ordinary.
The harvest seasons can be classified as such: the first (Spring/Summer) gave grain, the second (Summer) gave grapes, and the third (Summer/Fall) gave olives, figs, and more.
The first, of grains, was smaller in weight — because the other harvests were water-dense — but the biggest source of food, as it made up over 50% of the Jewish diet. Christ’s Crucifixion and Resurrection, even though He was merely one Man, are key in the same way.
Notable is that the second big harvest had grapes, and this was just after the wheat was brought in. Perhaps this is a Eucharist reference, relatable to the Church. At every event, bread and wine were crucial. These are also necessary to every Mass, at which they are confected into our new manna, which, like the old, sustains us until we reach the Promised Land. Christ’s Blood redeems and strengthens us. We already have the todah, the ultimate Sacrifice of thanksgiving and praise (CCC #1359-1361), which our rabbinical brethren await!
The third, which has the feast of tabernacles/booths, is important to the Second Coming. This can also be referred to as “the Ingathering”. The great festival involved imagery of water and light, which points toward baptism and Christ as the Light of the world (John 1:4-11). At His Return, Christ will reveal Himself to all as their rightful King (Zechariah 14:16), just as He revealed Himself to the Jews as the ultimate Teacher around this important feast (John 7:1-16). He will then perform His own, final Harvest and gather His flock to Himself (Matthew 13:24-30). At this, we will perpetually celebrate all of His wondrous deeds, just as the Israelites celebrated all of the year’s harvests (Deuteronomy 16:13-15).
Typology of the olives and figs is important, too. Olive oil was used to burn the lamps continually (Leviticus 24:2), and so the rule of God, at Christ’s Return at the olive harvest, will last forever. Jesus calls us to join Him under the security and sweetness of the fig tree and learn from Him (Micah 4:1-5, Zechariah 3:8-10) and be grafted into the eternal olive tree (Psalm 52:8, Romans 11:13-32).
Why did God allow for the striking-down of people in the Old Testament? How is this reconciled with the dogma of a loving God?
Protestants and modern-day “Jews” don’t have an answer for this — one beyond dualism or “mystery”, I mean. But the Church does.
There is mortal sin, and there is venial sin (1 John 5:17). Mortal sin — willful and of grave nature — separates one from God, practically killing the soul. Venial sin — all other — must simply be cleansed, and it does not eternally separate us from Him. And this distinction is shown in the Old Testament.
Among mortal sins punished: irreverence (2 Samuel 6:1-7), despair/disbelief (Numbers 11:1-3), and false claims of authority (Numbers 16). These crimes have always been condemned.
Why did punishment change from body-centric to soul-centric? First, it didn’t, because unrighteous people were also kept from entering the Limbo of the Patriarchs, which, after Christ’s Sacrifice, later led to Heaven. Second, temporal punishment was the only way to get at the Jews’ consciences: As liberal scholars love to point out, the majority of Jews did not believe in an afterlife!
God does not desire death, though it can be used to give us the best chance at salvation (2 Peter 3). (I think here of St. Rita and her sons.) Even in the old days, He merely wanted a contrite heart (Psalm 51:17), and He wanted devotion.
There is no change in principle: God is immutable.