Is it permissible to use phrases such as "you and I succeeded in doing so and so" or "the body was able to" when explaining the functions of organs, knowing that the true Doer is God, and this is by way of metaphor?

Actions and attributes performed by creatures are truly attributed to them. The belief that servants are not truly active, that their actions are metaphorically attributed to them, and that Allah is truly the doer of their actions, is an innovative (bid'i) saying. The people of Sunnah (definition) believe that the servant has power, will, and action, and is truly a doer, and Allah is the Creator of all that, as indicated by the Qur'an and Sunnah. Allah has affirmed the servant's will, and informed that it does not occur except by the will of the Lord Almighty. Servants act, make, work, believe, and disbelieve, and they have ability and strength. The imams of the Sunnah say that Allah is the Creator of all this. Creation, in their view, is not the created thing. So, the actions of servants are created and brought into being by the Lord. The servant's action, in the sense of the infinitive, is his action and not an action of the Lord Almighty.