The truth is that those who claim to have the promise of the first verse are actually making the error of people in the second verse.
Is that so difficult to see?
That's not exactly true.
First verse:
Psalm 91:10-12
10
There shall no evil befall thee, neither shall any plague come nigh thy dwelling.
Compare with...
Second verse:
Amos 9:10
10 All the sinners of my people shall die by the sword, which say, The evil shall not overtake nor prevent us.
Firstly, context.
Psalm 91
1 He that dwelleth in the secret place of the most High shall abide under the shadow of the Almighty.
2 I will say of the Lord, He is my refuge and my fortress: my God; in him will I trust.
3 Surely he shall deliver thee from the snare of the fowler, and from the noisome pestilence.
4 He shall cover thee with his feathers, and under his wings shalt thou trust: his truth shall be thy shield and buckler.
5 Thou shalt not be afraid for the terror by night; nor for the arrow that flieth by day;
6 Nor for the pestilence that walketh in darkness; nor for the destruction that wasteth at noonday.
7 A thousand shall fall at thy side, and ten thousand at thy right hand; but it shall not come nigh thee.
8 Only with thine eyes shalt thou behold and see the reward of the wicked.
9 Because thou hast made the Lord, which is my refuge, even the most High, thy habitation;
10 There shall no evil befall thee, neither shall any plague come nigh thy dwelling.
Regarding this passage, your assertion is that those who claim to have the promise of verse 10 are making the mistake of those who make the claim in Amos.
This presupposes that those who claim the promise in verse 10 are wrong.
Even in verse 2, the writer affirms trust in God that these things are so. You would say the psalmist is wrong?
Of course, we need to be careful in applying old covenant doctrine to the new covenant, much confusion resulting in legalism can result.
Just the same . . .
There is a simple statement of cause and effect,
9
Because thou hast made the Lord, which is my refuge, even the most High, thy habitation;
10
There shall no evil befall thee, neither shall any plague come nigh thy dwelling.
Compare to:
Amos 9
8 Behold, the eyes of the Lord God are upon the sinful kingdom, and I will destroy it from off the face of the earth; saving that I will not utterly destroy the house of Jacob, saith the Lord.
9 For, lo, I will command, and I will sift the house of Israel among all nations, like as corn is sifted in a sieve, yet shall not the least grain fall upon the earth.
10 All the sinners of my people shall die by the sword, which say, The evil shall not overtake nor prevent us.
There is a similar, and equally incorrect presupposition being made here also, in that all who claim the Lord's promise for good are sinners, and also are therefore wrong.
These are Sweeping Generalizations, by definition inaccurate, and, while I know many people won't care about that, these negate your assertions.
Much love!