Hi John1
Prayer always helps, and is usually the most sure fire way of getting answers to any questions you have. You must remember that it is the Spirit of God that helps us to understand the Bible. Without that Guy, we would be lost, so always good to ask for His help in understanding His Word.
"Knowing this first, that no prophecy of the scripture is of any private interpretation. For the prophecy came not in old time by the will of man: but holy men of God spake [as they were] moved by the Holy Ghost." (2 Pet 1:20-21) so if He was the one moving the men who wrote, who better to go to than to Him
with regard to your question, I also don't have a 100% 'thus sayeth the Lord' answer, though it is my understanding as from what I have studied so far (which is not much mind you
)
during the exodus, when the people were leaving Egypt, they still had no real understanding of God. due to the fact that they were in a foreign land where people did not worship or do as God would have wanted. They came from a land flowing with other gods and idol worship, and so God had to specifically tell them how to act, what to do, what not to do etc. thats why i think Exodus and Deuteronomy and all those books are like filled with rules and regulations. God was trying to bring His people back to a knowledge of Him and to get them back on the right path. i mean they had just seen all the plagues n Egypt, then walked through the Red Sea. yet when Moses 'delays' on the mountain, they go and make an idol to worship!! so you can say they did not really understand or trust God after being in Egypt for so long. so i view it as God gave all those harsh and straightforward laws (such as kill the witch!!) in order to get them right. they were so far gone that they needed drastic measures to be brought back!
now with today, i think we are at a different place. please understand that i think witchcraft and such is very wrong and it draws you closer to the devil instead of God. if you think about it, it is a sin. and all sin is simply wrong. yet, at the same time, all sins are equal. for if you break 1 commandment, you are guilty of all (James 2:10). so you will need to pray for your friends, that they might turn from their ways and be saved. just as you would if they were drug addicts. help them where you can, pray for them daily, but most of all, show them the Love of Christ. when He caught you in sin, He did not zap you straight away!! so show them the same patience and Love that He showed to you.
i know i digressed a bit (i just read through it now
) but hope it helps man.
Much Love yo!!