Mordecai

Mordecai is mentioned 52 times in the King James version of the Bible. 

50 of those occurrences are in the book of Esther.

The name Mordecai is in Ezra 2:2 and Nehemiah 7:7

When people forgot about God and turned to the senses realm for help, God was hidden from them, but because of God's eternal promises he is still at work although not visible to those who aren't looking.

In the book of God is not mentioned Esther. The name Jehovah, yehovah, adon, el, elah, elohim and eloah is not mentioned even once.  God is hidden in the book of  Esther. E.W. Bullinger in Appendix 60 of the Companion Bible refers to 4 acrostics have God's names hidden in the translation of Hebrew to English. They are Esther 1:20, 5:4, 5:13, 7:7 as (Lord) Jehovah h. They are Esther 1:20, 5:4, 5:13, 7:7 as 'Lord' (Jehovah YHVH) and another acrostic  in 7:5 as 'I am' (EHYH)

Bullinger refers to Deuteronomy 31: 16-18

 16And the LORD said unto Moses, Behold, thou shalt sleep with thy fathers; and this people will rise up, and go a whoring after the gods of the strangers of the land, whither they go to be among them, and will forsake me, and break my covenant which I have made with them. 17 Then my anger shall be kindled against them in that day, and I will forsake them, and I will hide my face from them, and they shall be devoured, and many evils and troubles shall befall them; so that they will say in that day, Are not these evils come upon us, because our God is not among us? 18 And I will surely hide my face in that day for all the evils which they shall have wrought, in that they are turned unto other gods.

When Israel turned to idols they turned their back on God and therefore incurred many problems.

God had promised in Genesis 3:15 that there would be a coming Messiah, so even though hidden He was still at work.