It seems to me that many Christians are confused by the injunction to Hope.
Surely it is a vital truth that Christians must Hope - yet I often see this grossly (and sometimes anti-Christianly) misinterpreted and misapplied into a foolish and unrealistic optimism about This World; which amounts to the denial of Hope.
For example, Christians may look at The World - at the state of the churches, politics, or any social institution; at the character and behaviour of some political, religious or business leader - and in effect they will refuse to take seriously the overwhelmingly negative and pessimistic signs and trends; because they must (they assume) be 'hopeful'.
This amounts to a gross failure of discernment due to a failure even to try and discern; asserting a non-Christian kind of non-judgmentalism which is actually a denial of spiritual responsibility.
Or, it may be a fear of despair; the sense that if we really took a serious and measured account of states and trends then we would be plunged into despair - and therefore they fall back on an assertion of 'Hope' which is actually a kind of dishonest optimism.
The distinction between optimism and Hope is that optimism is about this world, while Hope is about the next.
Jesus promises those who follow him, that their reward will be resurrected life everlasting in Heaven - but (obviously) he did not promise that life for his followers would be 'Heavenly' in this world.
(And if he had made such a promise of worldly happiness, then by now it has been refuted so many times that it would make Jesus a liar.)
Hope is indeed the antidote to despair; but this Christian Hope is a product of Faith - not of a fixed attitude of doctrinal optimism such as that things might get better, somehow; anybody might suddenly repent and reform, despite everything - and so on.
Of course any such thing might happen and cannot be ruled-out; but that is not a reason to ignore, explain-away, let alone excuse evil when we have good reason to discern evil.
Faith is not about Hoping that God will intervene to make everything right in this world; Faith is a confident belief in our transformation into Sons and Daughters of God after death.
If we are using Faith and Hope as excuses not to discern, or as an excuse for cowardice and lack of principle; that is actually itself a type of sin - a turning-away-from God.
So, let's take care not to do it - despite the frequent temptations!