These are spots in your feasts of charity, when they feast with you, feeding themselves without fear: clouds they are without water, carried about of winds; trees whose fruit withereth, without fruit, twice dead, plucked up by the roots [Jude 12].

Again let me share with you Dr. Wuest’s translation, which makes the description of the apostate teachers even more vivid:

These are the hidden rocks in your love feasts, sumptuously feasting with you without fear, as shepherds leading themselves to pasture, waterless clouds carried past by winds, autumn trees without fruit, having died twice, rooted up.

What a picture we have here!
“These are spots in your feasts of charity.” The word spots is better translated “hidden rocks” by Dr. Wuest. The picture is of hidden rocks which wreck a ship. They make what Paul calls “shipwreck” of the faith, and Paul names two men who evidently ran into an apostate, a hidden rock, and made shipwreck of the faith (see 1 Tim. 1:19–20). An apostate may be comparedto the tip of an iceberg. Very little of it is visible, but if a ship runs into it, the ship will go to the bottom of the sea. Oh, how many people there are, especially young people, whose faith has not only been shaken but wrecked by a person who is an apostate!
“These are spots in your feasts of charity.” The “feasts of charity” were love feasts which were held in the early church before the communion service. It was a time of fellowship when believers brought food and shared a meal together. The poor could bring very little, but it was a time of sharing what they had. Well, the apostates came in with ravenous appetites. They could eat more than anyone else—“feeding themselves without fear.” They were shepherds who were feeding themselves instead of their flock. Not only in the matter of food but also in their failure to teach the Word of God to their flock, it was evident that they were concerned only about themselves.
Milton describes this kind of situation when he writes of his friend, Lycidas. In his poem, he expresses his grief for the young man who had been a great preacher and expositor of the Word but was drowned in the Irish Channel. Milton describes the situation in England as it prevailed in his day: “The hungry sheep look up and are not fed.” What a picture of an apostate in the pulpit!
“Clouds they are without water.” They may look as if they are filled with the Word of God, but they are empty and dry. They may wear robes and speak in pompous, pontifical voices with great authority. They have had courses in public speaking and homiletics, and they know how to spiritualize a text of Scripture and make it mean something entirely different from what God intended. They are like beautiful clouds that drift across the sky without giving any refreshment to the earth.
In my boyhood days I can remember chopping cotton in the summertime and watching the clouds pass over. Oh, how I prayed for rain so I could quit chopping cotton, but there was no rain in those clouds. They were nothing but snowy white puffs. There was no water in them at all. Well, that is Jude’s picture of apostates. They do not have the water of life. They actually know nothing about the Word of God.
“Trees whose fruit withereth, without fruit, twice dead, plucked up by the roots.” When the Lord Jesus gave the warning against false teachers, He said, “… by their fruits ye shall know them” (Matt. 7:20). Jude says that the apostate has withered fruit, he is “twice dead, plucked up by the roots.” It was Dwight L. Moody who said that when a man is born once, he will have to die twice and that when a man is born twice, he will have to die only once. Well, Jude says that the apostates are spiritually dead, dead in trespasses and sins—and yet trying to lead others! Also the apostate’s body will have to die; so he is twice dead. What a picture of the apostate—and Jude is not through with him.  McGee, J. V. (1991). Thru the Bible commentary: The Epistles (2 and 3 John/Jude) (electronic ed., Vol. 57, pp. 104–106). Nashville: Thomas Nelson.

2 Pe 2:13 the wages of unrighteousness. Immorality and arrogant boldness will not pay in the end. It will rob and destroy. carouse in the daytime. Sinning during the day without the cover of darkness was a sign of low-level wickedness in Roman society (cf. 1 Thess. 5:7). But these false teachers are so consumed with lust and rebellion that they are pleased not to wait for the night. Their unbridled passions consume them. spots and blemishes. Cf. Jude 10. That is, dirt spots and scabs. They are opposite to the character of Christ (1 Pet. 1:19). The church should be like her Lord (Eph. 5:27). carousing … while they feast with you. The false teachers, feigning to be teachers of truth while sitting with Christians at church love-feasts, were behaving arrogantly and immorally even on such occasions intended for Christian fellowship. Though attempting to cover their corruption with religious talk, they were filthy defects on these church gatherings (cf. 2 John 9–11; Jude 12).
2:14 eyes full of adultery. The false teachers had so totally lost moral control that they could not look at any woman without seeing her as a potential adulteress (cf. Matt. 5:28). They were uncontrollably driven by lust, never resting from their sins. enticing unstable souls. The metaphor is from fishing and appears also in v. 8. To beguile is to catch with bait. False teachers do not capture those strong in the Word, but prey on the weak, the unstable, and the young in the faith (see 3:16; cf. Eph. 4:14; 1 John 2:13). heart trained in covetous practices. The word “trained,” was often used for training in athletics. The false teachers have trained, prepared, and equipped their minds to concentrate on nothing but the forbidden things for which their passions lust. They are well schooled in the craft of self-fulfillment. accursed children. This is a Hebraism for the curse of sin being the dominant thing in their lives, thus saying that they are damned to hell for their blatant wickedness. Cf. Gal. 3:10, 13; Eph. 2:1–3; 1 Pet. 1:14.
2:15 forsaken the right way. The “right way” is an OT metaphor for obedience to God (cf. Acts 13:10). Balaam. Cf. Jude 11. Balaam served as an illustration and example of such false prophets. He was an OT compromising prophet for sale to whomever paid him, who preferred wealth and popularity over faithfulness and obedience to God (Num. 22–24). Through a talking donkey, God kept him from cursing Israel (v. 16; cf. Num 22:21–35).
2:17 wells without water. In this verse, Peter uses two poetic figures (“wells” and “clouds”) which represent a precious commodity in the Middle East. A well without water would be a major disappointment in a hot and dry land. Likewise, false teachers have a pretense of spiritual water to quench the thirsty soul, but they actually have nothing to give. clouds carried by a tempest. The coming of clouds would seem to promise rain, but sometimes the storm would blow the clouds on by, leaving the land dry and hot. The false teachers might seem to promise spiritual refreshment, but were all show with no substance (cf. Jude 12). the blackness of darkness. That is, hell (cf. Matt. 8:12; Jude 13.) MacArthur, J., Jr. (Ed.). (1997). The MacArthur Study Bible (electronic ed., pp. 1956–1957). Nashville, TN: Word Pub.