Imagine that we emit a light pulse. As is the nature of light, it will expand. However, light is affected by gravitational fields and light has its own. Therefore, will the light converge given infinite time and infinite distance to travel interrupted?
Answer
No, or at least not under normal circumstances.
Calculating the gravitational force between light beams turns out to be rather complicated, so let's use an analogous but simpler system. Instead of a spherically symmetric pulse of light consider an explosion that throws out a spherically symmetric cloud of light particles.
At any time $t$ the cloud of particles will have some radius $r(t)$ and total mass $m$, so the escape velocity at the surface of the cloud is just:
$$ v_e = \sqrt{\frac{2Gm}{r(t)}} $$
If the velocity of the particles is greater than $v_e$ then the cloud will carry on expanding forver. If the velocity is less than $v_e$ the cloud will recollapse. So whether the cloud expands forever depends on how great the particle velocity is compared to the gravitational forces. The fact that a gravitational force exists does not necessarily mean the cloud must recollapse.
Now consider our light pulse. Unless the intensity of the light is so great that it creates a black hole the escape velocity will always be less than $c$ and the light will escape to infinity.
If you're interested in some background then have a look at the question Do two beams of light attract each other in general theory of relativity?. In particular note that parallel light rays do not attract each other due to gravity so a parallel ray of light will not gravitationally focus itself.
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