There is no excuse here for the lazy preacher who fails to prepare his sermon out of the mistaken reliance upon the Holy Spirit. Note this aorist participle with the future verb. Indirect aorist middle indicative. In Mark alone. Explains the sovereign choice of God in the end by and for himself.
Gullibility is no mark of a saint or of piety .
Credulity ranks no higher than scepticism. God gave us our wits for self-protection. Christ has warned us beforehand. Future passive indicative. One should not forget that prophetic imagery was not always meant to be taken literally, especially apocalyptic symbols.