We are told we are made in the image of God which I suppose is good. However, our being made in God's image doesn't keep us people from being really bad. Christianity tells us that we are all sinners falling short of God's glory. We simply cannot be trusted to make our own moral decisions and should trust God to make those decisions for us. In fact, "if there is no God, then everything is permitted." And of course, we sinful people will do that which should not be permitted!
As we are told in Psalm 14:
As we are told in Psalm 14:
Are we really that bad?The fool says in his heart,
“There is no God.”
They are corrupt, their deeds are vile;
there is no one who does good.
2 The Lord looks down from heaven
on all mankind
to see if there are any who understand,
any who seek God.
3 All have turned away, all have become corrupt;
there is no one who does good,
not even one.
4 Do all these evildoers know nothing?
They devour my people as though eating bread;
they never call on the Lord.
5 But there they are, overwhelmed with dread,
for God is present in the company of the righteous.
6 You evildoers frustrate the plans of the poor,
but the Lord is their refuge.
7 Oh, that salvation for Israel would come out of Zion!
When the Lord restores his people,
let Jacob rejoice and Israel be glad!