Alma briefly returns to the problem of time. It is possible that this time itself is unfair, or unjust of God. Since the time must be longer for those who have died long before the mission of the Atoning Messiah, an accusation might be leveled against God that he is unfair to those who must wait longer. Alma’s answer to this implicit question is to note that the time is irrelevant, as “all is one day with God, and time only is measured unto men.”
What he is saying is that this space between death and resurrection comes in another realm where time is counted differently. While we may see it is long, and therefore significant, to the Lord and his way of reckoning, it is a trifle. Were we told that we had to wait for some reward, and that some would wait two seconds and some three and some four, there is no one who would complain. The complaint about the unjustness of the time is apt only if the time is significant. What Alma is saying, then, is that what appears to us to be significant time will be insignificant time when seen in the reckoning of the Lord. Since the time is insignificant (two seconds as opposed to four seconds in our example) the one cannot levy the charge of being unjust against the Lord.