True Christians will always be in conflict (spiritually and philosophically) with non-Christians.
John 3:3-8
3 In reply Jesus declared, "I tell you the truth, no one can see the kingdom of God unless he is born again."
4 "How can a man be born when he is old?" Nicodemus asked. "Surely he cannot enter a second time into his mother's womb to be born!"
5 Jesus answered, "I tell you the truth, no one can enter the kingdom of God unless he is born of water and the Spirit. 6 Flesh gives birth to flesh, but the Spirit gives birth to spirit. 7 You should not be surprised at my saying, 'You must be born again.' 8 The wind blows wherever it pleases. You hear its sound, but you cannot tell where it comes from or where it is going. So it is with everyone born of the Spirit."
(from New International Version)
Rom 7:5-6
5 For when we were controlled by the sinful nature, the sinful passions aroused by the law were at work in our bodies, so that we bore fruit for death. 6 But now, by dying to what once bound us, we have been released from the law so that we serve in the new way of the Spirit, and not in the old way of the written code.
(from New International Version)
Rom 8:5-8
5 Those who live according to the sinful nature have their minds set on what that nature desires; but those who live in accordance with the Spirit have their minds set on what the Spirit desires. 6 The mind of sinful man is death, but the mind controlled by the Spirit is life and peace; 7 the sinful mind is hostile to God. It does not submit to God's law, nor can it do so. 8 Those controlled by the sinful nature cannot please God.
(from New International Version)
Gal 5:16-24
16 So I say, live by the Spirit, and you will not gratify the desires of the sinful nature. 17 For the sinful nature desires what is contrary to the Spirit, and the Spirit what is contrary to the sinful nature. They are in conflict with each other, so that you do not do what you want. 18 But if you are led by the Spirit, you are not under law.
19 The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery; 20 idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions 21 and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God.
22 But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, 23 gentleness and self-control. Against such things there is no law. 24 Those who belong to Christ Jesus have crucified the sinful nature with its passions and desires.
(from New International Version)
Gal 6:7-8
7 Do not be deceived: God cannot be mocked. A man reaps what he sows. 8 The one who sows to please his sinful nature, from that nature will reap destruction; the one who sows to please the Spirit, from the Spirit will reap eternal life.
(from New International Version)
Eph 2:1-3
2:1 As for you, you were dead in your transgressions and sins, 2 in which you used to live when you followed the ways of this world and of the ruler of the kingdom of the air, the spirit who is now at work in those who are disobedient. 3 All of us also lived among them at one time, gratifying the cravings of our sinful nature and following its desires and thoughts. Like the rest, we were by nature objects of wrath.
(from New International Version)
Rom 1:18-32
18 The wrath of God is being revealed from heaven against all the godlessness and wickedness of men who suppress the truth by their wickedness, 19 since what may be known about God is plain to them, because God has made it plain to them. 20 For since the creation of the world God's invisible qualities-his eternal power and divine nature-have been clearly seen, being understood from what has been made, so that men are without excuse.
21 For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened. 22 Although they claimed to be wise, they became fools 23 and exchanged the glory of the immortal God for images made to look like mortal man and birds and animals and reptiles.
24 Therefore God gave them over in the sinful desires of their hearts to sexual impurity for the degrading of their bodies with one another. 25 They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creator-who is forever praised. Amen.
26 Because of this, God gave them over to shameful lusts. Even their women exchanged natural relations for unnatural ones. 27 In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed indecent acts with other men, and received in themselves the due penalty for their perversion.
28 Furthermore, since they did not think it worthwhile to retain the knowledge of God, he gave them over to a depraved mind, to do what ought not to be done. 29 They have become filled with every kind of wickedness, evil, greed and depravity. They are full of envy, murder, strife, deceit and malice. They are gossips, 30 slanderers, God-haters, insolent, arrogant and boastful; they invent ways of doing evil; they disobey their parents; 31 they are senseless, faithless, heartless, ruthless. 32 Although they know God's righteous decree that those who do such things deserve death, they not only continue to do these very things but also approve of those who practice them.
(from New International Version)
1 Peter 4:1-5
4:1 Therefore, since Christ suffered in his body, arm yourselves also with the same attitude, because he who has suffered in his body is done with sin. 2 As a result, he does not live the rest of his earthly life for evil human desires, but rather for the will of God. 3 For you have spent enough time in the past doing what pagans choose to do-living in debauchery, lust, drunkenness, orgies, carousing and detestable idolatry. 4 They think it strange that you do not plunge with them into the same flood of dissipation, and they heap abuse on you. 5 But they will have to give account to him who is ready to judge the living and the dead.
(from New International Version)
"Sin lies only in hurting other people unnecessarily. All other 'sins' are invented nonsense." --Robert A. Heinlein