Why were the Children of Israel not effected by those plagues?
Exo_8:22 And I will sever in that day the land of Goshen, in which my people dwell, that no swarms of flies shall be there; to the end thou mayest know that I am the LORD in the midst of the earth.
Exo_9:26 Only in the land of Goshen, where the children of Israel were, was there no hail.
Was it because they followed the instructions of God, instead of man?
Heb_10:25
Not forsaking the assembling of ourselves together, as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching.
Read Hebrews chapter 11 if you want to understand the consequences of following God, instead of man.
Heb 11:35 Women received their dead raised to life again. Others were tortured, not accepting deliverance, that they might obtain a better resurrection.
Heb 11:36 Still others had trial of mockings and scourgings, yes, and of chains and imprisonment.
Heb 11:37 They were stoned, they were sawn in two, were tempted, were slain with the sword. They wandered about in sheepskins and goatskins, being destitute, afflicted, tormented—
Heb 11:38 of whom the world was not worthy. They wandered in deserts and mountains, in dens and caves of the earth.
Heb 11:39 And all these, having obtained a good testimony through faith, did not receive the promise,
Heb 11:40 God having provided something better for us, that they should not be made perfect apart from us.
Corrie Ten Boom spent time in a Nazi concentration camp, and her sister died there.
She understands persecution.
In the following video an American woman reads a letter Corrie wrote during the 1970's.
.