Please analysis and explanation of this quoteAuthenticity is achieved in self-transcendence, and consistent self-transcendence is reached only by conversion.
Since, this sentence does not have a context, it will be difficult to say what it really means. As you probably know context changes everything.
If we put this within a Christian context, then it means that true authenticity can only be achieved by transcending yourself and this only can take place when there is a conversion.
To put it another way, conversion leads you to think beyond yourself, your own desires, and your own myopic view of your world. When this happens, in a sense you transcend yourself, as you are able to look at other things and other people. We can say that at this point, you are feel from yourself. When this happens, you are able to live an authentic life.