Onely be thou strong, and of a most valiant courage, that thou mayest obserue and doe according to all the Lawe which Moses my seruant hath commanded thee: thou shalt not turne away from it to the right hande, nor to the left, that thou mayest prosper whithersoeuer thou goest.
Joshua 1:5 There shall not a man be able to withstande thee all the dayes of thy life: as I was with Moses, so will I be with thee: I will not leaue thee, nor forsake thee.
Joshua 1:6 Be strong and of a good courage: for vnto this people shalt thou deuide the lande for an inheritance, which I sware vnto their fathers to giue them.
Joshua 1:7 Onely be thou strong, and of a most valiant courage, that thou mayest obserue and doe according to all the Lawe which Moses my seruant hath commanded thee: thou shalt not turne away from it to the right hande, nor to the left, that thou mayest prosper whithersoeuer thou goest.
Joshua 1:8 Let not this booke of the Law depart out of thy mouth, but meditate therin day and night, that thou mayest obserue and doe according to all that is written therein: for then shalt thou make thy way prosperous, and then shalt thou haue good successe.
Joshua 1:9 Haue not I commanded thee, saying, Be strong and of a good courage, feare not, nor be discouraged? for I the Lord thy God will be with thee, whithersoeuer thou goest.
The verse centers on "onely", "thou", "strong", "most", "valiant", "courage", and "mayest". It is saying that the verse draws attention to "onely" and "thou", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 6's "Be strong and of a good courage..." into verse 8's "Let not this booke of the Law...", so "onely" and "thou" belong inside that flow. In Joshua context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "onely" and "thou" with trust shaped by these words, not by a vague optimism outside the passage.