The nature and purpose of deception is when someone is deceived by a lie, they considered it to be good enough to eat or partake of. The tree of knowledge was a tree of good and evil fruit, and God planted that tree in the midst of the garden. The fruit of that tree was off limits to Adam and his wife but not to the serpent. If they ate of the fruit they would die. The wages of sin is death (Rom 6:23). Sin is the fruit of deception and death is the result of sin. If sin is the fruit of deception then deception is the tree that bore the fruit. The tree of knowledge was a tree of deception that involved the knowledge and fruit of good and evil. Deception has a good part and an evil part and the end result for both is always death. Read the following;
Deut 30:18-30 'I denounce unto you this day, that ye shall surely perish, and that ye shall not prolong your days upon the land, whither thou passest over Jordan to go to possess it. I call heaven and earth to record this day against you, that I have set before you life and death, blessing and cursing: therefore choose life, that both thou and thy seed may live: That thou mayest love the LORD thy God, and that thou mayest obey his voice, and that thou mayest cleave unto him: for he is thy life, and the length of thy days: that thou mayest dwell in the land which the LORD sware unto thy fathers, to Abraham, to Isaac, and to Jacob, to give them'.
Human righteousness, in all of its forms is produced from the good part of the tree of knowledge. Unrighteousness, in all of its forms, is produced from the evil part of the same tree. God's righteousness comes from God and is the fruit the tree of life (Prov 11:3, 3:18, 15:3,4, Rev 2:7, 22:2,14,15). Sin entered into the world because of the fruit of good and evil that was consumed through disobedience. Sin entered through deception that lead to disobedience and the entire human race was conceived in that sin and shapened in the iniquity of it (Ps 51:5). Yes, deception is sin and the result is death.