2 Timothy 4:14-15, "Alexander the metalworker did me a great deal of harm. The Lord will repay him for what he has done. You too should be on your guard against him, because he strongly opposed our message."

Interesting points:
1. In these verses, Paul specifically warns Timothy about a particular person, "Alexander the metalworker (some translations say “coppersmith”)” who strongly opposed the gospel, so much that his ongoing actions proved an ongoing problem even as Paul wrote this letter.

2. Paul was not afraid to warn the flock by naming wolves when the situation called for it. Alexander was an extremely common name during this era, given the legacy of Alexander the Great of Macedonia. In the New Testament, there are at least three Alexanders mentioned -- in Mark 15:21 and Acts 4:6 and 19:33. The man Paul refers to here is most likely the same Alexander mentioned in 1 Timothy 1:20, who Paul "handed over to Satan." Some theologians believe this is the same Jewish Alexander in Ephesus found in Acts 19:33–34.

3. Paul's comments here indicate that he does not view Alexander as a believer. Paul's referencing Psalm 28:4 reminds us that God will hold those that persecute His people and attempt to impede His message accountable.

4. Knowing Alexander’s temperament, character and nature, Paul warned Timothy to forearm him with the truth concerning Alexander’s ability to cause trouble and spiritually harm the flock. This conflict is not the result of personality differences; rather, it stems from Alexander’s staunch opposition to the Truth concerning Jesus and the Good News concerning our redemption through Him.

Application.
Brothers, Paul’s warning Timothy provides us an excellent example of how to protect other believers from spiritual harm. In Matthew 10:16-17, Jesus tells His disciples, “Behold, I am sending you out as sheep in the midst of wolves, so be wise as serpents and innocent as doves. Be on guard against men [whose way or nature is to act in opposition to God]; for they will deliver you up to councils and flog you in their synagogues,…”
Like Paul, our words should plainly identify who/what to watch out for and not be laced with gossip. They should leverage the truth of God’s Word, reinforce that He is in control and be offered with the aim of sparing God’s beloved people from the dangerous influence, evil designs and lies of those influenced/controlled by our adversary, the devil.

May we be discerning in identifying the intent of others and wise in our choice of words to protect those in the path of evil men!