Foremost among these are mysticism and the idea of immanence. For though I wrote in the previous post that God Immanent should always stand in the light of God Transcendent that does not mean that the immanence of God should not also be acknowledged and, not only acknowledged, but actively sought. Christianity has become an exterior sort of religion, seemingly concerned with belief, doing good, being a good neighbour and so on. Doing just enough to be saved but otherwise leading a fairly normal life; indistinguishable, in fact, from a nonbeliever in many respects. This is not what Jesus taught nor is it, in my opinion, what we are put on this earth to achieve. We are here to learn to become godlike ourselves as in the well known saying that God became Man so that Man might become God.
So I would not recommend a conventional Christianity as the way forward to anyone. What we need nowadays is a mystical Christianity that sees Christ as a forerunner and exemplar of what we ourselves should be. This is not disrespectful or hubristic because it can only happen when we give ourselves entirely to God. And it is not a question of divinisation of the earthly man (which is a New Agey sort of concept) but of a new man being born, one in whom the seed of Christ has blossomed and flowered. It is a matter of getting to the state where we can say with St Paul that "I have been crucified with Christ. It is no longer I who live, but Christ who lives in me." What the New Age can take from Christianity is the need for crucifixion of the self. What Christianity can take from the New Age is the idea that we and Christ are truly one and that our purpose in life is to realise that. But we can only realise it when we empty ourselves of self and do what we do for God's sake not our own. For if we would become godlike it must be on God's terms and conditions not ours.
Christianity has been led astray, I believe, by a focus on salvation as its end. Salvation, as in turning to God and away from self, is crucial, of course. It requires repentance and redirection but it is only the beginning of the true spiritual path. It is stepping onto the path but it is not treading it to its conclusion which is found in the attainment of oneness with God or what is called theosis in the Orthodox tradition. This idea is clearly implied in Christianity but has been rather neglected because, I would say, it is so hard. But the goal of real Christianity has always been to make saints and we should not be satisfied with less.