One of the most basic reasons people in general, and believers in particular, distrust God relates to His goodness. Trusting God is at the very heart of man's purpose on the Earth: to glorify Him and enjoy Him, forever. Yet, from the very outset, Satan managed to convince Eve, then Adam, that God could not be trusted. At the heart of his temptation, and at the core of her falling, was the questioning of God's goodness. The enemy insinuated that He was holding out on her, that His restriction was unfair, that He couldn't really be trusted to act in their best interest. In short -- He isn't completely good.
The Accuser's tactics haven't changed a bit... He does all he can to get us to focus on all that is terrible in this world, with the whispered thought, "See? He allows this, and this, and that... He can't be trusted... how can He really be good?" And, since we tend to embrace as true only what our five senses experience, we believe his "half truths" (which is only another name for lies). In so doing, at least two things occur: (a) We impugn the character of the living God; and (b) we walk by sight, rather than by faith.
Psalm 119:68a reads, "You are good and do good." Interestingly, the context in which David affirms the character of God as good is having experienced afflictions. "It is good for me that I was afflicted," he declares in verse 71, which was used as a tool by the Lord to teach him His truth. Indeed, David confesses that "before I was afflicted I went astray, " (v. 67). What a contrast in perspective from that of the world! The world views affliction as a sign that God isn't good after-all...that suffering's afflictions indicate His impotency or indifference. When believers "buy the lie" of this perspective, it is a deplorable reflection on the goodness of the One who loves us beyond description, whose promises are thus slandered and whose faithfulness is discounted.
To the degree that we live lives that are not grounded upon His goodness, is the degree to which we walk by sight... giving the lie to II Corinthians 5:7. And the degree to which we do this is the extent to which our lives bear little difference from those who disdain our Lord. For, it is a life of faith that distinguishes the Christian from lost folk. In truth, the unseen realm is more real than the one that daily assaults our senses. For, "the world is passing away, and also its lusts...but the one who does the will of God abides forever." Oh, that the truth of God's immutable goodness would permeate our every attitude, mark our every action, and be reflected in our every word!