We are taught to read for a purpose and that purpose is to learn as well as to comprehend what we have read. The most read book in all of history, is the Bible, and not too surprisingly, since the Bible has a beginning in the book of Genesis, and an ending in the book of Revelation, many people, attempt to read it just like we would any other ordinary book, but, the Bible is not an ordinary book. While there isn't necessarily anything wrong with approaching the Bible from that reading perspective, in fact, it can be the right thing to do, there is also, though, a darker side to the equation to which a knowledgeable person should warn or instruct us about.
First off, the Old Testament is very long, to which, according to wordcounter.net the Old Testament has roughly 622,700 words, whereas the New Testament has 184,600 words, as compared to a typical novel which is somewhere around 80,000 words. In addition, to the sheer length of the Old Testament, we have the fact that many stories contained within it, contain stories and names that are convoluted, confusing to follow, and also often make no good conscious impression upon us. What does jump out at us, especially in today's relatively civilized conditions, is that the God of the Old Testament, appears rather violent and angry in His own actions, or the actions of the people that are directed to obey his dictates, such as in: 1 Samuel 15:3 "Now go, attack the Amalekites and totally destroy all that belongs to them. Do not spare them; put to death men and women, children and infants, cattle and sheep, camels and donkeys," as well as Numbers 16:35 "And fire came out from the Lord and consumed the 250 men who were offering the incense." On the other hand, in 1 John 4:7 we read: "Beloved, let us love one another, for love is from God, and whoever loves has been born of God and knows God."
The fact is that apologetics write endless amounts of commentary, instructing us that the God of the Old Testament is the same as the New, and these commentaries go on and on and on, with all sorts of justifications and circuitous logic, but all of this protest, seems to run along the lines as in "they had it coming". In fact, truth be told, there were legitimate concerns by those professing faith in Jesus the Christ, that there must be two Gods, and that the God/Father of Jesus, was the God, who replaced the former, and it is this God that we pay homage to today. Yet, of course, it's understood that God is perfect, omniscient, omnipotent, immutable, and so forth, so obviously there can't actually be two competing Gods or two Gods in which one was for back then, and this one is for now, but the Bible doesn't make it easy to reconcile this seemingly rather large divide.
Perhaps, there is another way to look at the apparent difference between the God of the Old Testament and of that of the New, and that is of mankind, itself. The more materialistic that man is, the more warlike that man is, the more injustice that man reins upon the other, necessitates, at times, drastic reactions from He would not be mocked. If man aggrandizes unto himself, that he is the measure of all things, that he is a god in of itself, that he can do whatever he desires, whenever, and to treat his fellow man as his personal plaything or slave, without concern towards the God that is within each of us, there must be an appropriate response from a loving God. That response can be a prophet or that response can be a plague, or a flood, or a Savior, and so forth, as God's toolkit is unlimited. At each and every point, though, God provides a sanctuary for those that will listen to that still, clear voice, whereas for those that are too hard-hearted to do so, they surely will reap the whirlwind of free will run amok, resulting in catastrophic events, because those that shut out the Light, will birth darkness, until such time that that Light can be born again.
God is the same, yesterday, today, and tomorrow, so that the God of the Old Testament is told to us in a way that sells us the illusion that makes it appear that God can be arbitrary, capricious, and cruel, whereas these portrayals are really better understood as man's attempt to comprehend the greatest force in all of Creation, to which, in the role of our Divine Mother, our Creator in actuality patiently waits for our return to that which is endless love.