1 John 5:16 states, “If anyone sees his brother sinning, if the sin is not deadly (venial), he should pray to God and he will give him life. This is only for those whose sin is not deadly. There is a such a thing as deadly (Mortal) sin, about which I do not say that you should pray”.
St. Paul writes St. Timothy calling the “unruly, the godless and sinful, the unholy and profane, those who kill their fathers or mothers, murderers, the unchaste, sodomites (homosexuals), kidnappers, liars, perjurers, and whatever else is opposed to sound teaching, according to the glorious gospel of the blessed God, with which I have been entrusted” (1 Timothy 1:9-10).
St. Paul also writes, “Do you not know that the unjust will not inherit the kingdom of God? Do not be deceived; neither fornicators (premarital sex) nor idolaters nor adulterers nor boy prostitutes nor sodomites nor thieves nor the greedy nor drunkers nor slanderers nor robbers will inherit the kingdom of God” (1 Corinthians 6:8-10).
Galatians 5:19-21 warns, “Now the works of the flesh are obvious: immorality, impurity, licentiousness, idolatry, sorcery, hatreds, rivalry, jealousy, outbursts of fury, acts of selfishness, dissensions, factions, occasions of envy, drinking bouts, orgies, and the like. I warn you,as I warned you before, that those who do such things will not inherit the kingdom of God”.
Those things which St. Paul warns about are what St. John calls “deadly sin”. Much of this that the bible addresses have become interwoven in our society.