Why God didn't send Jesus earlier if He knew that this is the only way to get saved?
It all has to do with 7 days or one week since Adam.
Genesis > God [Jesus] created the heavens and the earth in six periodic times and rested on the seventh
period of time. One symbolic week, made up of six days of work and one day of rest from work.
Adam is formed, not created, on the eight "day," and with his wife blows it with God and is expelled.
This was six thousand years ago, give or take a year. Six days of Bible history.
Three thousand five hundred (3,500) years ago [half-a-week] Moses gave to the Children of Israel the Law received from God.
The second coming of Jesus Christ as the great God of creation in all his power and glory [with myriads
of angels] is imminent, perhaps later this year or by next year 2018.
This will complete the six days of work - Old and New Testaments - and usher in the seventh day -
the millennium in which Jesus shall rule the world (Psalm 2) from Jerusalem and the Third Temple.
Thus six thousand years of Bible history from Adam plus one thousand years of Godly government =
one symbolic week of salvation Israel/Church history.
We see similar again with the ministry of Jesus - three-and-half years. Which fulfills Daniel's prophecy
of the first coming of the Messiah.
27 And he shall confirm the covenant with many for one week:
and in the midst of the week he shall cause the sacrifice and the oblation to cease, and for the overspreading of abominations he shall make it desolate, even until the consummation, and that determined shall be poured upon the desolate.
Daniel 9:27
Thus one week or seven years from the start of Jesus' ministry (which began when he was baptized
by full immersion and received the Holy Spirit) is made up of:
1: three-an-half years of Jesus preaching the gospel and performing wondrous miracles, culminating in
his death, burial and resurrection for the atonement of our souls.
2: three-an-half years after Jesus' ascension into heaven Cornelius and his household receive the
indwelling Holy Spirit and thus gentiles come into a covenant relationship with God.
That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
Ephesians 2:12