Starting yesterday, and for the next 49 days until Pentacost, Christians celebrate the Easter season. This season commemorates the Resurrection of Jesus of Nazareth.
Belief in the Resurrection separates religious Christians from philosphical Christians.
The Christian Left movement is philosophical and religious.
It is philosophical because one need not believe in the resurrection to adopt the ideals preached by Jesus, including the forgiving of sins as a condition for their forgiveness, charity to the poor and a humanistic morality which has the Sabbath existing for man rather than man for the Sabbath. From these prospects, a whole society can be devised without reference to a belief in the resurrection.
You can even go so far as to say one can be saved from one's sins on earth by Jesus without having any reference to eternal life. In fact, this is the best way to understand the difference between salvation and eternity. (I don't use the term justification, since we have no right to expect to be made just - however we can be released from our domination by sin in this life by calling on the Lord and drinking his blood, and can be forgiven by forgiving others).
Going to heaven is an entirely different matter.
We go to heaven when we behave as if we were saved from sin. Works do not save us from sinfullness - Jesus does that. Once we have been saved from sinfullness, we must then behave as members of God's family. Some people who do not believe in God already behave as Christians should - the Brights or ethical atheists. According to the parable of the sheep and the goats, they go to heaven as well - while some of those who claim Christ but do not act on their salvation will be numbered among the goats.
Of course, Easter is not for atheists, even if some of them will wind up in heaven.
Easter is the promise that we do not stay dead. We will rise one day and go to heaven (the experience of heaven before the resurrection - or how we exist in time after death - or if we do - is a matter for the dead. The scriptures seem to indicate that once one has escaped the world, one has escaped time itself and may just land at the last judgment. This is one of those things that we don't need to worry about, since worrying about it won't change it anyway.
So, for those who are religious Christian Leftists, Happy Easter!