From the additional notes to Charles Spurgeon's The Treasury of David, on Psalm 119, verse 86.
All thy commandments are
faithful. David sets down here three points. The one is that God is true; and
after that he adds a protestation of his good conduct and guidance, and of the
malice of his adversaries: thirdly, he calls upon God in his afflictions. Now
as concerning the first, he shows us that although Satan [intends] to shake us, and in the end
utterly to carry us away, subtly and cunningly goes about to deceive us, we
must, to the contrary, learn how to know his ambushes, and to keep us from out
of them. So often then as we are grieved with adversity and affliction, where
must we begin? See Satan how he pitches his nets and lays his ambushes to
induce and persuade us to come into them, what saith he? Dost thou not see
thyself forsaken of thy God? Where are the promises whereunto thou didst trust?
Now here thou sees thyself to be a wretched, forlorn creature. So then thou
right well sees that God hath deceived thee, and that the promises whereunto
thou trusts appertain nothing at all unto thee. See here the subtlety of Satan.
What is now to be done? We are to conclude with David and say, yet God is true
and faithful. Let us, I say, keep in mind the truth of God as a shield to beat
back whatsoever Satan is able to lay unto our charge. When he shall go about to
cause us to deny our faith, when he shall lie about us to make us believe that
God thinks no more of us, or else that it is in vain for us to trust unto his
promises; let us know the clean contrary and believe that it is very plain and
sound truth which God saith unto us. Although Satan casts at us never so many
darts, although he have never so exceeding many devices against us, although
now and then by violence, sometimes with subtlety and cunning, it seems in
very deed to us that he should overcome us; nevertheless he shall never bring
it to pass, for the truth of God shall be made sure and certain in our hearts.
— John Calvin.