The common belief in most Christian sects are reducible simply to a yielding to God. Phrase it however you want: We're saved by works / faith / righteousness / non-judgement / accepting Jesus Christ as your personal savior [every day] / whatever! As different as these "ways" may be, they all at least entail a yielding to God.
Now, we often divide ourselves on terminology too hastily. Jesus, properly understood, is "simply" the meeting of God and Earth. He is the Earthly presence that glorifies God. His very name is YHWH is salvation. And God, properly understood, is the very act of being itself. His name, YHWH, is I AM WHO AM. To yield to God is to yield to the act of being itself. To follow Christ, to be a member of His body, is to proclaim the importance and saving nature of yielding to God -- to yield more fully, in a sense.
So, if we "unload" our terminology for a moment, an atheist may very be living in acceptance of Jesus without fully recognizing Jesus as the savior in Christianity. That is, an atheist may very well perceive there to be an underlying, essential, transcendent act of being. And the atheist might pursue this absolute and center his life around it. But, on account of poor, uneducated, or tactless Christian evangelization, he may have no idea the transcendent act of being he "worships" is our God, or that this underlying universal order has anything to do with our Jesus Christ.
Now, while I'll advocate that anyone (at all) can conceivably get through the pearly gate through their own yielding to God, by whatever name they know Him, I'll certainly also insist that some religions provide better directions so we don't find ourselves picking the lock with the wrong tools at the wrong gate. and as a Catholic, I'll suggest our chances are best of yielding to the appropriate God, as opposed to a counterfeit or delusion, when we have solid Catholic tools in our belts! I am, of course, talking about Catholic tradition, doctrine, and sacraments.
We can be quick to count folks with differing beliefs as saints while continuing to believe they're wrong, in danger, or in need of significant clarification on Christian beliefs!