Was God Cruel in the Old Testament But Kind in the New?

I have heard many people say that the God of the Old Testament was harsh, cruel and mean, implying that they did not like “that” God; but the God of the New Testament is loving, kind, patient and gracious – not like the God of the Old at all! But is this description of God correct? Did God change in the New Testament?? Let’s talk about that! | Genesis 6:3, 15:13-16; 2 Peter 3:9