What does the Bible say about ungodly men in the church?

In Jude 4, it is stated that certain men have crept in unawares into the church, who were previously ordained to condemnation. These ungodly men are characterized by their actions, which include turning the grace of God into lasciviousness, denying the only Lord God, and rejecting the person and work of Jesus Christ. This describes a serious spiritual threat within the church, as these individuals can influence teaching and disrupt the true faith. The presence of such men reveals the necessity for believers to earnestly contend for the faith that was once delivered to the saints.