Christian’s often affirm that ‘God is good’. But, we often confuse the sense in which this sentence is applied to life situations.
As a Christian, one must acknowledge the foundational truth that God is good intrinsically (Deut. 32:4; Nah. 1:2,7; Jas. 1:13), namely, in Him ‘there is no variation or shadow due to change’ (Jas. 1:13). God’s goodness is never contingent on any event within created order (good or evil). One must acknowledge that it is different to speak of God being good, and something being good in the sense that it is favorable, a type of prescriptive good, which can be relative to the evaluator (for a good discussion see Bruce Little, A Creation Order Theodicy).
Also, while this distinction exists, it is important to note that nothing within this world can be prescriptively good without a necessary being, God, who is intrinsically good. This distinction is often blurred when dealing with the more difficult situations of life, leading some to conclude that God’s benevolence towards creation should be questioned since experience attests to the horrible realities of evil and suffering. Some would be tempted to conclude, based on the experiences of life that ‘God is not good’, a notion that the Christian must reject (Deut. 7:7-8; Jn. 15:9-17; 1 Jn. 4:10; Ps. 145:16).
God’s goodness is closely related to different aspects of His nature, “among them love, mercy, patience, and grace” (Wayne Grudem, Systematic Theology), and must be treated together in unity. God is the final standard of good, for He himself is good.
Matt Capps 
God is good. But by which standard of goodness is He good? From where has that standard originated? If God is the alpha and omega of existence, then that standard can originate from God only. Therefore if God is good, then He is good by His own standard of goodness. But a person, or a being, cannot, and should not, be judged good by his own standard of goodness. This standard must have to be independent of him. Otherwise Hitler will also claim that his action be judged by his own standard. And he will claim that he has done nothing wrong by killing 6 million jews, because he thought it absolutely necessary. So, if God is the alpha and omega of existence, then God cannot be good.