Post History

Out sinful desires come from our fallen bodies (our flesh).

> For if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body, you will live.
> 
> Romans 8:13

> Let no one say when he is tempted, “I am being tempted by God,” for God cannot be tempted with evil, and he himself tempts no one. <sup>14</sup> But each person is tempted when he is lured and enticed by his own desire. <sup>15</sup> Then desire when it has conceived gives birth to sin, and sin when it is fully grown brings forth death. 
> 
> James 1:13-15

> But our citizenship is in heaven, and from it we await a Savior, the Lord Jesus Christ, <sup>21</sup> who will transform our lowly body to be like his glorious body, by the power that enables him even to subject all things to himself.
> 
> Philippians 3:20-21

So it is also crucial that we receive new/regenerate bodies, so our own desires no longer entice us to sin.

> So is it with the resurrection of the dead. What is sown is perishable; what is raised is imperishable. It is sown in dishonor; it is raised in glory. It is sown in weakness; it is raised in power. It is sown a natural body; it is raised a spiritual body. If there is a natural body, there is also a spiritual body.
>
> 1 Corinthians 15:42-44

As to why God chose to allow us to fall, there is some answer. I think the argument is that God's love and character can be made more wonderful to us by our starting in a fallen state and being exalted from that.

> You will say to me then, “Why does he still find fault? For who can resist his will?” <sup>20</sup> But who are you, O man, to answer back to God? Will what is molded say to its molder, “Why have you made me like this?” <sup>21</sup> Has the potter no right over the clay, to make out of the same lump one vessel for honorable use and another for dishonorable use? <sup>22</sup> What if God, desiring to show his wrath and to make known his power, has endured with much patience vessels of wrath prepared for destruction, <sup>23</sup> in order to make known the riches of his glory for vessels of mercy, which he has prepared beforehand for glory—
>
> Romans 9:19-23

As shown above, though, it is not for us to question His purposes. We are of lower stature and have lower thoughts than His, so it doesn't necessarily matter what we think, only that we trust His will with faith.

<sub>All verses are taken from the English Standard Version (ESV).</sub>