19 Do not quench the Spirit. 20 Do not despise prophecies, 21 but test everything; hold fast what is good. 22 Abstain from every form of evil. 
For many years in my Christian walk I heard verse 22 used to admonish Christians to avoid going into places that might be misunderstood by people in the form of compromising our Christian faith. For example if I were to walk into a bar with a friend to have a conversation with him, the admonishment would be “you need to abstain from the appearance of evil for your testimony’s sake.” In other words, unbelievers might misunderstand my intentions and thereby think that I had taken to getting drunk and that would not have been a good thing to have on my record in the court of public opinion. If we were to take that logic to its uttermost conclusion then neither should a Christian attend a sporting event in a stadium where beer is sold.
Unfortunately all of this buffoonery happens when we take a scripture out of context and use it to speak about our own opinions. Paul the Apostle in this text was concerned about the misuse of spiritual gifts and wanted to caution the Thessalonians from throwing the baby out with the bathwater. Apparently there was much misuse of the gifts of the Holy Spirit such as weird prophetic utterances that it was causing the Thessalonian Christians to be tempted to just ditch all the utterances if weirdness was going to show up when the gifts were used. Paul admonishes them, “Don’t do that, because you will be quenching the Holy Spirit and thus not allowing the Holy Spirit free reign in your midst.” Instead, Paul tells them to test all the gifts, to see if they are Biblical or not, hold onto the good and ditch the weirdness. It certainly had nothing to do with avoiding the chariot races because your Christianity might be compromised.
This Scripture of course is very applicable to the church today. There have been a lot of weird things happen in Christian circles under the guise of the working of the Holy Spirit that really should be tested and ultimately ditched. But by all means, we should remember to keep the good as we ditch the bad. Who knows what we might miss if we throw the baby out with the bath water?
A good example of this is the true story of a dear lady who tired of her pastor preaching against Santa Clause every Christmas season. Finally, she had enough and stood up in the morning worship service and announced in a loud voice, “Thus saith the Lord, ‘lay off Santa Clause. He’s a good man doing a good work for the children,’” and promptly sat down. Truth be known, both the lady’s message and the pastor’s message haranguing Santa Clause instead of preaching from the Bible, should have been ditched according to Paul’s admonition.
So in our churches, let’s take Paul’s admonition seriously and use our spiritual gifts in the church, examine spiritual gifts in the church. Throw out the weirdness and cling to the good. In doing so, we will certainly not be quenching the Holy Spirit. Also, in sticking to how this Scripture might be properly applied, we may actually do some good, going as salt and light into areas of darkness to talk to a friend about eternal life, even if it ends up being a bar.
 The Holy Bible: English Standard Version. (2001). (1 Th 5:19–22). Wheaton: Standard Bible Society.