The Bible tells how we are to approach it. One can only approach the interpretation and understanding of the Bible through the guidance of the Holy Spirit. In order to obtain that guidance, there are many things that need to occur, but most simply, one must first accept the Holy Spirit's conviction of sin and the need for repentance. Then once one accepts that and realizes the need for a savior, one accepts Christ. At that point, one is "born of the spirit" the second birth. Finally, one must seek God's guidance in humility and remove sin from their lives.
This is why so many Christians have a confusing testimony. They will not rid themselves of sin. And you see it, they're not fooling you. They, if born again, are still a child of God, but will receive temporal punishment and the loss of eternal reward. I have personally had to get rid of many sins in my life at the prompting of the Holy Spirit. In fact, many of which had detrimental effects on my health requiring me to delve into fasting. Rock music is destructive to the adrenals, as is fast cars, high-adrenaline sports, stressful living, overindulgences, etc. The adrenals then take out the thyroid, and a cascade of health problems ensue.
The passage of which you refer does not mean there are righteous people in and of themselves. They were already believers. They were actively waiting for the Messiah as I am actively waiting for his return. They were already walking in God's will for their time. Christ came to save the lost, those who were confused and had not yet sought to follow God. But that doesn't mean the lost follow Christ. Only a few.
People before Christ were saved in Christ. The entire old testament is about Christ, the coming messiah. Christ appeared to Abraham, Moses, and many other prophets before his birth. He is the Alpha and Omega.
By going to the temple and sacrificing for one's sins, one recognized that one day God would provide his son as the final sacrifice. So the old testament saints looked forward to Christ just as the new testament saints look forward to his return. The entire Bible points to Christ.
The Bible tells us to "rightly divide" it. This is why there are so many confused Christians. They apply doctrines to themselves that don't belong. Take for instance 7th day Adventists, as an easy example. They say that Christians are to worship on the Sabbath, despite the fact that the Sabbath was a covenant between Israel and God, not the Church and God. The Apostolic example was to worship on the Lords Day , or the first day of the week, Sunday, the day of resurrection.
Very few Christians will be able to tell you how many divisions or "dispensations" there are and what they mean. Most don't realize that they know at least 2: Law and Grace. There are actually 7 total. They are seven different ways that God deals with man and they all require one thing: obedience. That's where we lose most people. We all know what's best for our lives, not God. This is tragic. And I apologize for any Christians that say that there are any other ways to God other than through the blood of His Son.
As for children suffering and dying, I understand your reservations. The Bible tells us that death and suffering entered the world through sin. When children die, not understanding sin and the need for repentance, they go straight to heaven. King David's bastard child with Bathsheba had to die according to God, even though he was innocent. David said, "I will go to him" acknowledging that one day they would be together in Heaven.
But we all need to remember that our sins have consequences. Look at the AIDS in Africa. Those poor children. It's sobering as a parent to understand the responsibility I have to avoid those sins which would hurt my children and live as an example to them.
But God give His children (and innocent children) this assurance:
"For I reckon that the sufferings of this present time [are] not worthy [to be compared] with the glory which shall be revealed in us."
Chris, I would encourage you to continue to ask "why" now, before Judgement Day. God appreciates those critical questions, just as long as you follow through and give him the chance to answer them. He's not insecure about being critiqued as long as it is honest and sincere.
"Come now, and let us reason together, saith the LORD: though your sins be as scarlet, they shall be as white as snow; though they be red like crimson, they shall be as wool."
"But without faith [it is] impossible to please [him]: for he that cometh to God must believe that he is, and [that] he is a rewarder of them that diligently seek him."