Oscar Wilde pointed to the importance of this word in his play performed in 1895. Although, centuries have gone by the importance of being earnest is still relevant today, both the play and the word. The Collins dictionary defines earnest as being serious in mind or intention, showing or characterised by sincerity of intention, a pledge, assurance, to be zealous or sincere. It goes on to say that, "Earnest people are very serious and sincere in what they say or do, because they think that their actions or beliefs are important." Taking this definition as Christians then, we should always be described as earnest.
One place we see the word earnest used in scripture is in Hebrews directed towards how Christians should receive God's word. In Hebrews 2:1 it writes, "Therefore we ought to give the more earnest heed to the things which we have heard, lest at any time we should let them slip." The Strong's concordance uses earnest in this passage for the word perissoteros. It describes the word earnest as, more abundantly, more earnestly, more frequent, much more.
If we put these definitions into the passage we can see that we ought to more abundantly, more frequently and with more zeal and sincerity heed (listen to) God's word and message of salvation. The warning for if we are not earnest in this passage is that we could let God's words slip treating them lightly and ultimately losing our salvation through apathy.
In the world today there are many people like the characters of the play who are not being earnest. Just like the characters, many lead double lives on social media, speaking and portraying themselves as someone who they are truly not. It is so much harder today to find people who are earnest. We should be able to say that the one place you will find them is in church, but sadly even this isn't always the case. Christianity is often worn as a jacket these days and just like with social media many switch personas in the different areas of their lives. Holy and heavenly on Sunday and laughing at the rude jokes in the lunch room on Monday.
In Hebrews we are directed to the importance of being earnest, which is in the form of a warning, that if we are not earnest we can let God's word slip. Letting God's word slip in our lives doesn't just affect us it also impacts others. The importance of being earnest doesn't just affect us and our reputation, as Christians it can affect others' views of God.