Like the packets of information travel according to the destination address written on them on the Internet, soul also has to travel according to the stamping that deeds create on the mind.
According to the deeds, the address of destination changes and soul has to go to hell, to heaven, to God's abode or to earth either as human or as other living animal or plant.
Packets cannot travel of their own, they need support of related hardware and software and of course electricity, similarly presence of God is essential to give the effect of deeds so that soul follows path according to its deeds and experiences sufferings and happiness, that is, happiness and sufferings are the effect of earlier deeds.
Thus, there is cause and effect relationship between our deeds and experiences. Therefore, God is said to be controller and soul a controlled object.