I'll give you some good words from God's instruction manual for righteousness. It's a little long, but these scriptures give you a good perspective of the difference between us and non-Christians. I'll answer your question about confession in the next message.
The extent of this may come as a surprise to you, but when we enter into covenant with God, He calls us out of the world's system, which is run by the god of this world, Satan.
"This I say therefore, and testify in the Lord, that ye henceforth walk not as other Gentiles walk, in the vanity of their mind, Having the understanding darkened, being alienated from the life of God through the ignorance that is in them, because of the blindness of their heart: Who being past feeling have given themselves over unto lasciviousness, to work all uncleanness with greediness."
Eph 4:17-19
When Jesus became our Lord and the Holy Spirit entered into us, we became temples of God Himself. We were set apart by Him to know and love and serve Him. We become partakers of the divine nature and like branches grafted into a vine, we partake of His life as we yield to His Spirit. We had our nature reborn as a new creature, now capable of fellowship with God. Our goal in this world, is to allow Him to flow within us in love and overcome the sin nature which is in the flesh. Doing this will bring the abundant life within us and the fruit of the Holy Spirit. He is the treasure in the field, of which we have sold everything to buy that field and partake of that treasure.
Those who have not been reborn, are literally in bondage to sin. All of their thoughts are estranged from God. No matter how "good" of a person they are, their lives are alientated from the life of God within.
And you, that were sometime alienated and enemies in your mind by wicked works, yet now hath He reconciled In the body of His flesh through death, to present you holy and unblameable and unreproveable in His sight:
Col 1:21-22
Consecrate yourselves to day to the Lord, even every man upon his son, and upon his brother; that He may bestow upon you a blessing this day.
Ex 32:29
And now come I to Thee; and these things I speak in the world, that they might have My joy fulfilled in themselves. I have given them Thy Word; and the world hath hated them, because they are not of the world, even as I am not of the world. I pray not that Thou shouldest take them out of the world, but that Thou shouldest keep them from the evil. They are not of the world, even as I am not of the world.
John 17:13-16
The people we "hook up with" are in essence scripturally, we people we yoke to. A "yoke" was something used to harness animals together to work together in the fields.
Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness? 15 And what concord hath Christ with Belial? or what part hath he that believeth with an infidel? 16 And what agreement hath the temple of God with idols? for ye are the temple of the living God; as God hath said, I will dwell in them, and walk in them; and I will be their God, and they shall be my people. 17 Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you, 18 And will be a Father unto you, and ye shall be my sons and daughters, saith the Lord Almighty.
2 Cor 6:14-18 (KJV)
"For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit. For to be carnally minded is death; but to be spiritually minded is life and peace. Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be."
Romans 8:5-7
Take heed to thyself, lest thou make a covenant with the inhabitants of the land whither thou goest, lest it be for a snare in the midst of thee: But ye shall destroy their altars, break their images, and cut down their groves: For thou shalt worship no other god: for the Lord, whose name is Jealous, is a jealous God:
Ex 34:12-14
If we're walking in the light, we wont' be able to flow with each other because we're not partaking of the same spirit. They'll be put off by your behavior which should convict them that they are sinners. Their choice based on that knowledge will be either to repent or to despise the very truths you base your life by.
And have no fellowship with the unfruitful works of darkness, but rather reprove them. For it is a shame even to speak of those things which are done of them in secret. But all things that are reproved are made manifest by the light: for whatsoever doth make manifest is light.
Eph 5:11-13
"Enter not into the path of the wicked, and go not in the way of evil men. Avoid it, pass not by it, turn from it, and pass away.
Prov 4:14-15
"Thorns and snares are in the way of the froward: he that doth keep his soul shall be far from them."
Prov 22:5
"Be not deceived: evil communications corrupt good manners. Awake to righteousness, and sin not;"
1 Cor 15:33-34
"An unjust man is an abomination to the just: and he that is upright in the way is abomination to the wicked."
Prov 29:27
"For this ye know, that no whoremonger, nor unclean person, nor covetous man, who is an idolater, hath any inheritance in the Kingdom of Christ and of God. Let no man deceive you with vain words: for because of these things cometh the wrath of God upon the children of disobedience. Be not ye therefore partakers with them."
Eph 5:5-7
"He that walketh with wise men shall be wise: but a companion of fools shall be destroyed."
Prov 13:20
"Ye did run well; who did hinder you that ye should not obey the truth? This persuasion cometh not of Him that calleth you. A little leaven leaveneth the whole lump."
Gal 5:7-9
Ye adulterers and adulteresses, know ye not that the friendship of the world is enmity with God? Whosoever therefore will be a friend of the world is the enemy of God. think that the scripture saith in vain, The spirit that dwelleth in us lusteth to envy?
James 4:4-5
"Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him. For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world. And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever."
1 John 2:15-17
"Pure religion and undefiled before God and the Father is this, To visit the fatherless and widows in their affliction, and to keep himself unspotted from the world."
James 1:27
"If the world hates you, ye know that it hated Me before it hated you. If ye were of the world, the world would love his own: but because ye are not of the world, but I have chosen you out of the world, therefore the world hateth you. Remember the Word that I said unto you, The servant is not greater than his lord. If they have persecuted Me, they will also persecute you; if they have kept My saying, they will keep yours also."
John 15:18-20
Who we hang out with influences us. That is why believers should fellowship with believers. It's a race and only the winners who abide by the rules win the prize. Although our lives are a witness to the world, their is a difference between bearing witness and fellowshipping. The spirits that unsaved people carry will try to quench the Spirit within you. Use wisdom in who you are spending your time with.