Llandaff Cathedral Choir the highest and holiest place

The highest and the holiest place
Guards not the heart from sin;
The Church that safest seems without
May harbour foes within.
Within that small and chosen band
Beloved above the rest,
One fell from his apostleship,
A traitor soul unblest.
But ne'er the great designs of God
Man's sin shall overthrow;
A better witness to the truth
Forth to the lands shall go.
Matthias was the chosen one -
God's purpose cannot fail -
The word of grace no less shall sound,
The truth no less prevail.
Righteous, O Lord, are all thy ways:
Long as the worlds endure,
From foes without and foes within
Preserve thy Church secure.