It may come as a surprise to some (particularly those who do not read for themselves, so many) that The Gospel of Mark has three alternate endings. In some of the manuscripts, things end with verse 8 “they were afraid.” Others have a longer ending containing what is today verses 9-20. Others have a shorter ending that is usually tacked on to the end of today’s printings. Still others do what most Bibles do today, which is include both endings. Even the old manuscripts tend to indicate that both longer endings are likely not original. The problem is that we do not have the original copy of Mark, so no one knows what the real ending looked like.
None of that is a problem.
Even if Mark stopped at “they were afraid,” there are multiple accounts of the Gospel, so we know that was not the end. Just a natural reaction to the events. And, the additions that are found on what persisted do not necessarily change the other accounts. It is just a good reminder to keep Biblical teaching in context and to not build entire doctrines from single verses in isolation.
Those sorts of interpretations—and the dangers there inherent—are seen in groups who take this passage to mean that believers must test their faith through stupidity. Handling snakes and drinking poison is no test of trust, but more like an ultimatum or dare thrust in God’s face. Akin to forcing God to prove Himself by keeping us from harm while we are walking down the middle of a busy highway or throwing ourselves from a plane with no parachute. That is silly.
However the other danger here is evident. We all too often add things to scripture and then lose the capacity to distinguish between God’s word and our own. Like when editors inserted marginal notes claiming that the creation occurred around 4004 BC. Sometimes these additions are not even in print, but merely a pet interpretation. Too many people have lost the ability to read God’s word because they only see their own ideas or understanding. While it is a good idea (in my opinion) to make notes in one’s Bible when insight and enlightenment are given, it is also a good idea to read scripture without those notes in place from time to time. Past messages tend to inhibit fresh readings.