Can Christians handle rattlesnakes?

I think this question is actually answered simply by showing the entire of Mark 16:18, emphasis mine:

they will pick up snakes with their hands; and when they drink deadly poison, it will not hurt them at all; they will place their hands on sick people, and they will get well

So the question of "can Christians handle rattlesnakes?" is no different to the question "can Christians cure people by laying-on-of-hands?" (I could also have chosen poison for the example).

To the question of healing, the answer is pretty much universally a resounding "no". There are of course anecdotal claims to "yes", and I really don't want to get into that debate again, but at least in the general case, the answer is "no".

The same applies to snakes. There will of course be anecdotal people who handle snakes; not getting bitten is merely a combination of luck, handling, and probably more than a little understanding of the animals behaviour. That doesn't make it risk free, any more than Roy's handling of tigers was risk free (although right until the end of his career all evidence would have suggested otherwise).

I'd answer this exactly the same as I did the other similar question:

Looking at how God's method of communication has changed over time, it should not be surprising that such "gifts" are not as common as they were. When it came to the Apostles and the early Church, God was specifically working to establish His Church. These signs and wonders were accompanied by preaching of the Gospel.

In fact, if you look at the miracles performed by Jesus Himself, you'll see that He performed them as a demonstration of His authority, and if you look at them in total, they display that He is God. http://www.aboutbibleprophecy.com/miracles.htm In other words, He didn't perform them merely to amaze people, He did them to support His teaching, authority, and claims about Himself.

With the Apostolic miracles, and those of the early Church, the pattern is similar. The miracles accompany the preaching of the Gospel, or serve to establish the authority of the Apostles, and early Church. Once the authority has been established, there is no further need for God to "prove Himself". He's already done so. He had already revealed Himself, and He did say specifically that if we don't believe in the Scriptures, why would we believe Him. (John 5:46). How many times does He have to prove Himself before we believe?

A similar pattern can be seen throughout Scripture. In the beginning, He walked with Adam and Eve and spoke to them personally. With Moses, He spoke from a burning bush. Later, He spoke to the people through Moses, and then through the prophets.

Also, God had shown anger several times throughout Scripture towards them that seek after signs, when He had already revealed Himself. He tolerates it at first, even though He recognizes it for what it is (temping God) (Exodus 17:7) but He is still angered by it. (Psalm 78:18-20)

Jesus also rebuked the Pharisees and Sadducees for the same thing. (Matthew 16:4)

That said, there are still those around today who believe that these verses are to be taken literally, and that they still apply today. These would be the snake handlers in a few Pentecostal denominations and sub-groups that so many people love to make fun of.

As for me, personally, I don't dare practice these rituals. It's not that I don't think that God could protect me from snakes and poisons. It's more that I know that this would be, to me, a test of whether or not He truly would. In other words, my actions would be a deliberate tempting of God. I fully believe that He could do it, but I don't want to make Him angry because He could just as well let me die simply because I had the audacity to test Him. Who am I to test Him?