"Being true to yourself" has become the defining piece of advice for living well in the 21^st century. It is also one of the most overused phrases in popular culture. If it's not Disney declaring the "follow your heart and be true to yourself" mantra, then you can guarantee talk show hosts, musicians, celebrities and self-help gurus will.

And people are buying into it. We are a society obsessed with authenticity. We have become preoccupied with discovering and expressing our "authentic" selves.

It's not hard to see why being true to oneself has such wide appeal. In our increasingly pluralistic society, where there are few agreed standards of behaviour, "being true to yourself" essentially allows people to live as they please. That is the logical end-point of embracing this kind of moral relativism. It encourages people to act upon what they feel or believe to be true, not necessarily what is objectively true or right. Essentially, "I'll decide what's right for me, and you decide what's right for you."

"Being true to yourself" may at first glance seem noble and courageous. The world applauds those who defy societal norms and "march to the beat of their own drum". But it is a philosophy that ultimately prioritises self over the welfare of others. And this is problematic in a world populated by selfish sinners.

All too often people justify inconsiderate and harmful behaviour to themselves or others simply by claiming they are being true to themselves. The adulterous spouse, the abusive boss, the spiteful gossip, and the dishonest friend can all claim: "But I'm being true to myself!" When authenticity becomes the moral ideal, other virtues like faithfulness, kindness, and humility are deemed less worthy than "being genuine".

Furthermore, to be true to yourself, you must know who you are. But we cannot know who we are because self-deception lies at the very core of our being. The prophet Jeremiah wrote:

The heart is deceitful above all things and beyond cure. Who can understand it?Jer. 17:9

Our minds cannot illuminate us to who we are any more than our feelings can. No amount of psychoanalysing or transcendental meditation will help us understand ourselves, for when we reject our Creator our thinking becomes muddled (Rom. 1:21). Self-knowledge can only come from God, when the Holy Spirit unveils to us the true state of our hearts and what the law of God requires (1 Cor. 2:15-16).

So when the world is telling us to be true to ourselves, how should we respond? For Christians, we should remember that our ultimate authority is God's Word and not our feelings. And our ultimate example is Jesus Christ. We are not called to be true to ourselves. Why? Because we are sinful by nature (Rom. 7:14); our natural mind is hostile to God (Rom. 8:7-8); we consider the things of God foolishness (1 Cor. 2:14); and our lives are hopeless without Him (Eph. 2:1, 12).

Rather, we are called to "put off (our) old selves" and to "put on the new self, created to be like God in true righteous­ness and holiness" (Eph. 4:22-24). If we are in Christ then we are a new creation (2 Cor. 5:17). We are to put to death our sinful nature and former way of life.

And we do so because in Christ our old nature has already been defeated, destroyed and replaced. God is calling us to live in step with what we already are and have - a new spiritual self (Col. 3). Perhaps then, the question we should be asking ourselves is: Are we living "true" to our new identity in Christ?