Nature
Temptation, the inducement to sin, occurs when man is confronted by a temporal good (recognized as such) which conflicts with his eternal good.
Background
In the Biblical sense, temptation is the situation in which man tempts his faith to God (having to choose between fidelity and infidelity to one's obligations to God) as well as tempting God Himself by testing Him to reward or punish.
Counter-claim
In one sense, temptation is man's lot; to escape all allurements of evil would require flight from this life.