God laughs
He that sitteth in the heavens shall laugh: the Lord shall have them in derision. Ps. 2:4
We need to remember that all the plans of the wicked have neither startled God, nor do they worry him. And when they carry out their schemes, God is not wringing his hands. What is he doing? He is laughing, not the nervous laugh of one who is not quite sure what to do next, but the laugh of derision. God is sovereign and on his throne, and even the wicked machinations of rebels will one day be shown to have redounded unto his glory and the good of his people.
God's laugh of derision helps us to put things in perspective. We can't see the end, and often we can't even imagine a good outcome to certain events. But we must remember that our perspective is limited and our knowledge is limited and our ability to wrap our minds around the infinitely tangled webs of human doings is limited - but God is not! God laughs because he does see the end, and it is an end in which the wicked perish and the righteous triumph. Let the wicked think what they want; let them laugh now. But God will have the final word, and he shall surely have them in derision.
So what should we do? We should do what the psalmist exhorts us to do, to serve the Lord with fear and to rejoice with trembling, to kiss the Son and gladly submit to him. Indeed, blessed are all who put their trust in him (11-12).