This is quite the opposite of the Christian view of human nature. Christianity tells us that we are far from the best we can be. It tells us that we are fallen and full of sinfulness. Of course, this is counter-balanced with the promise from Jesus that if we turn to him we will be perfected, and washed clean of our sin. But until such time as we have worked - with Jesus's help - to remove our selfishness, and be capable of self-denial then we are far from perfect. Certainly we should NOT be happy with who we are when we start that journey. To the Christian this realisation is not a cause for self-hatred, depression or despair. Rather it is a relief - Christians are glad that a path is available to free them from harming others through selfishess, and that that path will lead to a joyous everlasting life of love.
Thus it appears that these two world views are coming more and more into conflict. As G.K Chesterton stated we are facing a new world where sinners declare that they are saints, rather than the old one in which saints declared that they were sinners. Admitting one's sinfulness is a necessary - and therefore healthy - step towards happiness. Secular people are being denied this path, with the athiest promise that they are fine as they are - i.e that it is ok to have whatever faults or sexual or other desires they have - no matter how out of control those desires are. From the athiests' perspective the problem lies not with the sinful individual, but the judgementalness of others. They seek to change God's world to accommodate human sinfulness, rather than change the people to be accommodated by God. Thus the athiests' efforts are likely to drive non-Christian people further and further from God. They focus not on creating virtuous individuals but on creating a virtuous society through social activism. Unfortunately, such a thing is impossible - you can never have a virtuous society that does not consist of virtuous people (and certainly not without God as leader). What you will create instead is one variation of hell - the various disasterous social experiments of the 20th century bear testament to this truth..
In such a world Christians perhaps need to be reminded to ignore the secular values around them; to remember that Christians do not belong to this world, and instead to hold more tightly to Jesus' promises and keep their eyes instead on the glittering prize, regardless of what worldly suffering they may encounter.
"If we confess our sins, He is faithful and righteous to forgive us our sins and to cleanse us from all unrighteousness."
1 John 1:9
"but if we walk in the Light as He Himself is in the Light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin."
1 John 1:7