Habakkuk was a pupil of John Walker, congregational minister at Framlingham, and in 1766 Crabb proceeded to Daventry Academy under Caleb Ashworth.
On 25 February 1789, upon the death of Thomas Harmer, Crabb undertook the pastorate at his native place,[1] but his theology (he was probably an Arian) was too latitudinarian for the congregationalists of Wattisfield; he resigned the charge on 15 August 1790, and became minister at Royston.
Robert Hall delivered a funeral oration on New Year's Day 1795, assisted by another family friend, John Towill Rutt of London.
[2] Hall stated: ...the character of Mr. Crabb was too well established, and held in too high esteem, to have any thing to hope from praise, or to fear from censure.
The innocence and sanctity of his behaviour, the sensibility of his heart, the fidelity with which he discharged the duties of life, and the equanimity with which he bore its rebukes and sufferings, will leave a lasting impression on the minds of all his friends and acquaintance.