In the Law (the Torah), the Lord God wrote on the stone tablets with His very own finger,
"You shall not commit adultery." Ex 20:14; Deut 5:18

Matthew 15:19  "For out of the heart come evil thoughts, murders, adulteries , fornications, thefts, false witness, slanders.  20  "These are the things which defile the man...

Mark 7:21  "For from within, out of the heart of men, proceed the evil thoughts, fornications, thefts, murders,  adulteries ,  22  deeds of coveting [and] wickedness, [as well as] deceit, sensuality, envy, slander, pride [and] foolishness.  23  "All these evil things proceed from within and defile the man."

Lev 20:10  'If [there is] a man who commits adultery with another man's wife, one who commits adultery with his friend's wife, the adulterer and the adulteress shall surely be put to death.

Deut 22:22  "If a man is found lying  with  a married woman, then both of them shall die, the man who  lay   with  the woman, and the woman; thus you shall purge the evil from Israel.

John 8:3  And the scribes and the Pharisees brought a woman caught in adultery , and having set her in the midst,  4  they said to Him, Teacher, this woman has been caught in  adultery , in the very act.  5  "Now in the Law Moses commanded us to stone such women...

Heb 13:4  [Let] marriage [be held] in honor among all, and let the [marriage] bed [be] undefiled; for fornicators and  adulterers  God will judge.

James 4:4  You  adulteresses , do you not know that friendship with the world is hostility toward God? Therefore whoever wishes to be a friend of the world makes himself an enemy of God.

Eph 5: 5  For this you know with certainty, that no  immoral  or impure person or covetous man, who is an idolater, has an inheritance in the kingdom of Christ and God.  6  Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience.

Col 3: 5  Therefore consider the members of your earthly body as dead to  immorality , impurity, passion, evil desire, and greed, which amounts to idolatry.  6  For it is on account of these things that the wrath of God will come,

1 Thes 4:3  For this is the will of God, your sanctification; [that is,] that you abstain from sexual  immorality ;  4  that each of you know how to possess his own vessel in sanctification and honor,  5  not in lustful passion, like the Gentiles who do not know God;  6  [and] that no man transgress and defraud his brother in the matter because the Lord is [the] avenger in all these things, just as we also told you before and solemnly warned [you.]  7  For God has not called us for the purpose of impurity, but in sanctification.  8  Consequently, he who rejects [this] is not rejecting man but the God who gives His Holy Spirit to you.

Rev 21: 8  "But for the cowardly and unbelieving and abominable and murderers and  immoral persons and sorcerers and idolaters and all liars, their part [will be] in the lake that burns with fire and brimstone, which is the second death."

Rev 22: 14  Blessed are those who wash their robes, that they may have the right to the tree of life, and may enter by the gates into the city.  15  Outside are the dogs and the sorcerers and the  immoral  persons and the murderers and the idolaters, and everyone who loves and practices lying.

1 Cor 6:9  Or do you not know that the unrighteous shall not inherit the kingdom of God? Do not be deceived; neither fornicators, nor idolaters, nor  adulterers , nor effeminate, nor homosexuals,  10  nor thieves, nor [the] covetous, nor drunkards, nor revilers, nor swindlers, shall inherit the kingdom of God.

1 Cor 6:9  Or do you not know that the unrighteous shall not inherit the kingdom of God? Do not be deceived; neither fornicators, nor idolaters, nor  adulterers , nor effeminate, nor homosexuals,  10  nor thieves, nor [the] covetous, nor drunkards, nor revilers, nor swindlers, shall inherit the kingdom of God. 11  And such WERE some of you; but you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus Christ, and in the Spirit of our God.

John 8:3  And the scribes and the Pharisees brought a woman caught in adultery... 11b And Jesus said, "Neither do I condemn you; go your way. From now on sin no more."

1 John 1:9  If we  confess  our  sins , He is faithful and righteous to forgive us our  sins  and to cleanse us from all unrighteousness.  10  If we say that we have not  sinned , we make Him a liar, and His word is not in us.  2:1  My little children, I am writing these things to you that you may not  sin . And if anyone  sins , we have an Advocate with the Father, Jesus Christ the righteous;  2  and He Himself is the propitiation for our  sins ; and not for ours only, but also for [those of] the whole world.  3  And by this we know that we have come to know Him, if we keep His commandments.  4  The one who says, "I have come to know Him," and does not keep His commandments, is a liar, and the truth is not in him;  5  but whoever keeps His word, in him the love of God has truly been perfected. By this we know that we are in Him: