Peace vineshvk
Your presumption is that God is included in the subset of 'all things', it is a fallacious premise that leads you to conclude God will cease upon the end of time. Time is itself subject to end but not God.
As time stops, light stops and then there wouldn't be God. When there is no time, then no energy, no entropy and hence no God.
In philosophical point of view, if everything cease to exist then the concept of God is redundant. God exist in the minds of believers ( every living objects). If they dont exist when everything cease to exist, then God dies out with them.