The average believer would never consider the word joy to be an appropriate descriptive term for temptations. There is a great explanation for this as the average believer experiences little to no victory when tempted. Temptations put a man’s faith on trial. When his faith stands the test, he learns patience. Therefore, he sees temptation as a means by which he can grow in the Lord and add virtues such as patience. It is not that he finds joy in the temptation itself, but that God can and will use that temptation to make him "perfect and entire, wanting nothing" (James 1:4). Believers who fight through and obtain victory find joy in knowing that their faith pleases God (Hebrews 11:6).
Romans 3:4 says, “let God be true, but every man a liar.” Perhaps this truth serves as the foundational reason why God warned believers not to place their trust in man. Though the primary reason, it is not the only reason. In Psalm 146:3 the Lord warns, “Put not your trust in princes, nor in the son of man, in whom there is no help.” The real needs of mankind cannot be satisfied by man, even the best of men. Those who put their trust in man do so in disobedience to the Lord which results in their own personal harm. Psalm 118:8-9 twice stresses that “It is better to trust in the LORD.” An improper trust in man is, in many ways, a departure from the Lord (Jeremiah 17:5).
