2 Peter 3:3-7 NKJV
3 knowing this first: that scoffers will come in the last days, walking according to their own lusts, 4 and saying, “Where is the promise of His coming? For since the fathers fell asleep, all things continue as they were from the beginning of creation.” 5 For this they willfully forget: that by the word of God the heavens were of old, and the earth standing out of water and in the water, 6 by which the world that then existed perished, being flooded with water. 7 But the heavens and the earth which are now preserved by the same word, are reserved for fire until the day of judgment and perdition of ungodly men.
If you want the context of the verse you posted, it refers to those who do not believe that the Lord is returning soon and come against the brethren who are earnestly waiting and praying for His return for His bride.
And may I suggest Grace777x70, if you complain about "mockers" here, perhaps you should take care in regard to how you address people who believe something different than you, but what they believe is rooted and grounded biblically. It can come across as a bit mocking at times. Just a friendly suggestion.