I know us Catholics do not to talk about certainty because that belongs to the presumptous Protestants.

Once saved always saved.
Well, what I was saying, we understand our belief - the promise of eternal life, it is all there. In faith we believe it will come to pass, if we have reasonably followed and lived according to its teaching.
Our options as believers, given to us, are heaven and purgatory. The latter is really due to the mercy of God where we would be purified first before going to the former.
Catholic’s context of the funeral mass is always this - that the soul will go to heaven, or at least purgatory.
It is not about hell, because if it is, there is nothing we can do about it to reverse that destination. Most understanding Catholics would know this fact and agree with it.
Normally, on death bed, Catholics would be given Sacraments (Anointing the sick, Reconciliation and Eucharist) these are outward graces. Graces are what make us right with God as St Paul said.
Granted, even then, we may not be pure enough to enter heaven because there is such thing as stain of sin, but we are not going to hell instead it will be purgatory.
So we hold to this hope in faith.
It is such a shame for Catholics if when it comes to death that we forget all about our belief, that we are totally devoid of faith or forget what our belief is and succumb to the grief of death, in defeat.
This is contradictory to what Jesus and our early brothers in the faith taught us - that death has lost its sting.
The funeral mass/memorial services should therefore be a time of comfort for the relatives of the deceased, that these belief should be made known to them again through preaching, homily, scriptural readings and emphasis.
The raising of Lazarus from the dead was a foreshadow of the thing to come. More importantly from that passage we see by the presence of Jesus and his action (to raise Lazarus from the dead) brought immeasurable relief to the deceased’s relatives (logically).
This has been the hope for Christians - resurrection on the last day. This passage was painted in the catacomb of early Christians. In fact they even believed that the resurrection happened in their life time, and they just could not wait for it to happen.
Christians do not fear death. On the other hand, they embrace this reality in a positive manner, knowing what is in store for them after the death itself.
If we do not believe in what we were taught, then our faith is a lie. We are living a lie.