Fire is always fire. Put wood, hay, stubble, paper near a fire and it will combust and be reduced to ashes. Put iron near a fire and it takes the fire into itself. In time it will even glow with the heat of the fire and will communicate that fire to all it touches or that touches it.
When God draws near, that which is compatible with with Him takes Him in, is transformed and transfigured by Him, and like the iron communicates Him according to a person's nature and ability to receive fire. Those who are like wood, hay and stubble find His presence consuming. Those who are like iron…or better like gold and silver, receive Him and are purified by Him.
With respect to the Old Testament we also believe that God's revelation of Himself took time, and His people in possession in the early years of a limited revelation acted in that context. Yet there were great men of God in those years too, and we are not in a position to judge them by a set of mores that only became broadly viable after the establishment of the Church and the New Covenant. The Orthodox take many of the stories or significant aspects of those eras as spiritual metaphors/illustrations, not as material for broad emulation. So rather than literally dash anyone's little ones against the stones, we dash the hateful, sinful, tempting thoughts insinuated by the enemy before they have opportunity to root, grow, and become serious thorns and snares for us.
Since Christ we know much better what God wants of us and also have access to Him in a very intimate way in and through Christ. The Old Testament times were a time of hard and sometimes brutal lessons. Our sins as humanity had not yet been met in history in Christ, and until then God winked at a lot that was inconsistent with His fullest desires for the healing and restoration of man. Plus we may not forget, though we do not regard God as some vengeful potentate out to destroy us if we don't routinely lick His boots…He is still our God and the giver of our lives and the only one Who make take them or permit them to be taken. We will all die eventually. Even when He has permitted calamities of the body, that does not mean He has no care for the soul of one so taken.
In Christ God has shown us His Heart. It is there we must turn for the light to understand all else concerning Him before or in ages yet to come.