The majority of Christians teach that the Israelites were enslaved in Egypt for 430 years. This understanding comes from the Exodus text which says the following:
Exo 12:40,41 Now the sojourning of the children of Israel, who dwelt in Egypt, was four hundred and thirty years. And it came to pass at the end of the four hundred and thirty years, even the selfsame day it came to pass, that all the hosts of the LORD went out from the land of Egypt.
Pretty clear right? The only issue with a 430 years of enslavement is that it does not agree with the other details provided in the Scriptures, such as the age of the individuals who lived in Egypt from the time they arrived to the time they left.
For example, we know the following
Exo 6:18 And the sons of Kohath; Amram, and Izhar, and Hebron, and Uzziel: and the years of the life of Kohath were an hundred thirty and three years
Exo 6:20 And Amram took him Jochebed his father’s sister to wife; and she bare him Aaron and Moses: and the years of the life of Amram were an hundred and thirty and seven years.
Exo 7:7 And Moses was fourscore years old, and Aaron fourscore and three years old, when they spake unto Pharaoh.
Even if Kohath was born to Levi when he arrived in Egypt and Amram was born to Kohath, the year he died and Moses was born to Amram the year he died, still the calculation would be 133 + 137 + 80 = 350 from the arrival of Jacob in Egypt to the Exodus. So a 430 year period of enslavement is a physical impossibility.
Paul’s answer
Using Paul’s writings and the Book of Genesis we are able to put together a more accurate picture of what happened and why 430 years came to be mentioned in Exodus 12:40.
Gal 3:16,17 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ. And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.
If you read the above carefully, Paul mentions that the time between the Abrahamic Covenant and the Mosaic Covenant was 430 years. How did he arrive at this conclusion? The above date agrees with Josephus who says the following:
They left Egypt in the month Xanthicus; on the fifteenth day of the Lunar month; four hundred and thirty years after our fore-father Abraham came into Canaan. But two hundred and fifteen years only after Jacob removed into Egypt. Antiquities of the Jews, Book 2, Chapter 15
Answers in Genesis
If we look at the accounts in Genesis, we find out that the second part of Josephus’ mention(215 years till Jacob entered Egypt) agrees with scripture.
Gen 12:4 So Abram departed, as the LORD had spoken unto him; and Lot went with him: and Abram was seventy and five years old when he departed out of Haran.
Gen 21:5 And Abraham was an hundred years old, when his son Isaac was born unto him.
Gen 25:26 And after that came his brother out, and his hand took hold on Esau’s heel; and his name was called Jacob: and Isaac was threescore years old when she bare them.
Gen 47:9 And Jacob said unto Pharaoh, The days of the years of my pilgrimage are an hundred and thirty years: few and evil have the days of the years of my life been, and have not attained unto the days of the years of the life of my fathers in the days of their pilgrimage.
The above verses show us that there was 215 years from Abraham arriving in Canaan to Jacob entering Egypt with his family. Abraham was 75 when he entered Canaan. He was 100 when Isaac was born (100 – 75 = 25). Isaac was 60 when Jacob was born. Jacob was 130 when he entered Egypt. 25 + 60 + 130 = 215.
Which means that the Israelites lived in Egypt for a maximum of 215 years of which the period of Slavery is unknown, but could be no more than 150 as Joseph lived 70 years after Jacob entered the land of Egypt. (Gen 41:46, 45:6, 50:26)
The prophecy of 400 years of affliction
But there is another question which must be answered, as God himself made it known to Abraham that his children will be “strangers” in the land and will be afflicted 400 years.
Gen 15:13 And he said unto Abram, Know of a surety that thy seed shall be a stranger in a land that is not theirs, and shall serve them; and they shall afflict them four hundred years;
To resolve the apparent contradiction, we must understand that Abraham and his descendants lived in the land of Canaan and Egypt as strangers till the Exodus. We see this mentioned in the speech of Abraham and the letter to the Hebrews as follows:
Gen 23:4 I am a stranger and a sojourner with you: give me a possession of a buryingplace with you, that I may bury my dead out of my sight.
Heb 11:9 By faith he sojourned in the land of promise, as in a strange country, dwelling in tabernacles with Isaac and Jacob, the heirs with him of the same promise:
Afflicted by Ishmael
The 400 years of affliction was set off by Ishmael, as he was the first to trouble the promised heirs of Abraham. Paul makes this point in the Letter to the Galatians as follows, equating Ishamel (born after the flesh) to be persecuting Isaac (born after the spirit).
Gal 4:29 But as then he that was born after the flesh persecuted him that was born after the Spirit, even so it is now.
The Genesis account records the above in the following way:
Gen 21:8,19 And the child grew, and was weaned: and Abraham made a great feast the same day that Isaac was weaned. And Sarah saw the son of Hagar the Egyptian, which she had born unto Abraham, mocking.
An extra note must be made of the word “mocking” (Tsachak) which is also translated in Gen 26:8 as “sporting” which could mean that Ishmael was not merely mocking with words. If we take Isaac’s persecution at the hand of Ishmael to have happened when he was 5 years old (at the celebration when he was weaned), the 400 years of affliction falls into place naturally.
If Isaac was persecuted when he was 5 years old, the time from the start of affliction to the birth of Jacob would be 55 years (Gen 25:26). If we add Jacob’s sojourning in Canaan, which is 130 years (Gen 47:9) and the earlier established sojourning of 215 years in Egypt together we arrive at a 400 year period (55+130+215=400). Which means both the 430 years from Abraham to the Exodus and the 400 years of affliction are Scripturally accurate when looked at closer.
Abraham’s Covenant made on Passover
Looking and reviewing this text and this question leads us to another interesting deduction; which is that God made His Covenant with Abraham on a Passover. The Exodus account records that the time between the Exodus and the day that the promise was given to Abraham as recorded in Genesis 15, is the same day;
Exo 12:40,41 Now the sojourning of the children of Israel, who dwelt in Egypt, was four hundred and thirty years. And it came to pass at the end of the four hundred and thirty years, even the selfsame day it came to pass, that all the hosts of the LORD went out from the land of Egypt.
We know that the Children of Israel left Egypt on Passover, and if the start of the 430 year mark is at the making of the Abrahamic Covenant, as we examined above – then this means the Abrahamic Covenant was made on the 15th of the 1st month (Abib) which is Passover.
Conclusion
It is clear that the 430 years of Egyptian servitude is not based on the whole text of the Bible, and is a clear misunderstanding of the verses. There seems to be no contradictions in this regard, even though 400 years of affliction and 430 years of sojourning is mentioned in the Scriptures. Dates and ages are always given for a reason in the Bible, and examining them closer shows us a clearer picture and dispels any questions which may arise.
In the present day, words mean little to nothing. We see politicians say one thing but do another. We see governments amend founding laws of the land. It is even becoming impossible to trust a regular person’s word. The notion of a 
Bible things in Bible ways 