What is pride? What despair?

Pride and despair are sins - which is to say, all of both must voluntarily be relinquished, if we are to be fitted for Heaven. 

Pride is thinking we are "good enough", as we are - and without resurrection. 

Nobody - as-is - is good enough for Heaven; and there could be no Heaven unless this could be set right; and Jesus Christ would not have needed to die, if the problems of Men-as-is could be set right without passing-through death.

But we are not good enough, and this cannot be set right without passing-through death and re-making. 

Despair is in believing that we are essentially depraved - that is: depraved in our essence. 

Any Man, any Being, capable of love, is capable of choosing an eternal commitment to live by love, to his everlasting ruling motivation... 

No Man can make this happen by himself, from himself; nor can the commitment to live-by-love be made everlasting without passing-through death and being re-made from that which is Good in us. 

(Despair is also an eventual consequence of believing that this re-making after death is not a real possibility; or being convinced that we personally cannot have it; or of deciding that - although it is real and possible - we do not want it.)