First, it is true that ALL have sinned in one way or another. Simply looking at a woman in lust or coveting the neighbor's Porsche constitutes sin. Scripture says that "for all have sinned and fall short of the glory of God" Romans 3:23 There is nothing we can say to deny this. Even the Holiest of human beings walking this earth today is a sinner. Our nature at birth was a sin nature. We are all born sinners and only through the Grace of God and the righteousness imputed upon us through Jesus' blood shed on the Cross can we be presented Holy and blameless in the sight of God. The Divine Exchange where Jesus was nailed to the Cross for our sins thereby becoming the lamb without blemish (He was without sin) who took our sins upon himself and imputed His righteousness upon us ensured this for His generation and for all future generations of those who believed upon Him. For He was the second Adam, accomplishing God's purpose for mankind where the first Adam disobeyed God when He ate of the fruit of the tree of knowledge (good and evil) and thereby introduced sin into the world.
Second, it is not ours to judge another person's sin or sinfulness. We have become an extremely judgmental society where we pretend to understand, weigh, categorize or measure the sinfulness of other individuals and mete out swift punishment here and now in this world when it was never ours to judge others to begin with! A married man who lives the straight and narrow and obeys all the norms of society appears sinless to us whereas the drunk fool who visits prostitutes every night, gambles his money away and swears up a storm appears sinful to us. Judging others comes very easily if we are Rabbis, Clergy, Pastors, teachers of the law or the Bible. However, scripture warns us against judging another's sin. "Judge not, that you be not judged. For with the judgment you pronounce upon others, you will be judged, and with the measure you use to measure others, it will be measured to you. Why do you see the speck that is in your brother’s (any other person's) eye, but do not notice the log that is in your own eye? Or how can you say to your brother (any other person), ‘Let me take the speck out of your eye,’ when there is the log in your own eye? You hypocrite, first take the log out of your own eye, and then you will see clearly to take the speck out of your brother’s eye." Matthew 7:1-5 Indeed the right to judge others is not ours, nor was it ever ours. Only God has the right to pass judgement upon other people. So stop judging people, and start loving them, no matter who they are, just as Jesus did. He ate with sinners, prostitutes and tax collectors --- the lowest of the low in his time. "While Jesus was having dinner at Matthew’s house, many tax collectors and sinners came and ate with him and his disciples. When the Pharisees saw this, they asked his disciples, “Why does your teacher eat with tax collectors and sinners?” On hearing this, Jesus said, “It is not the healthy who need a doctor, but the sick. But go and learn what this means: ‘I desire mercy, not sacrifice.’ For I have not come to call the righteous, but sinners.” Matthew 9:10-17 This is the manner with which Jesus loved others, and nobody loved others as well as Jesus did.
Third, there is forgiveness of sin for all who confess, repent and turn from it, and leave their sinful ways behind.
"Blessed is the one whose transgression is forgiven, whose sin is covered.
Blessed is the man against whom the Lord counts no iniquity, and in whose spirit there is no deceit.
For when I kept silent, my bones wasted away through my groaning all day long.
For day and night your hand was heavy upon me; my strength was dried up as by the heat of summer. Selah
I acknowledged my sin to you, and I did not cover my iniquity; I said, “I will confess my transgressions to the Lord,” and you forgave the iniquity of my sin. Selah
Therefore let everyone who is godly offer prayer to you at a time when you may be found; surely in the rush of great waters, they shall not reach him.
You are a hiding place for me; you preserve me from trouble; you surround me with shouts of deliverance. Selah
I will instruct you and teach you in the way you should go; I will counsel you with my eye upon you.
Be not like a horse or a mule, without understanding, which must be curbed with bit and bridle, or it will not stay near you.
Many are the sorrows of the wicked, but steadfast love surrounds the one who trusts in the Lord. Be glad in the Lord, and rejoice, O righteous, and shout for joy, all you upright in heart!" Psalm 32
"If my people, which are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land. 2 Chronicles 7:14
"If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness." 1 John 1:9
"I came not to call the righteous, but sinners to repentance." Luke 5:32
Confession, therefore, must be honest and done with a remorseful and contrite heart.
Repentance, therefore, much be heartfelt and sincere,
and turning away from one's sin must be permanent --- not to be revisited again.