This is a question asked often enough by us poor mortals in "this vale of tears".
When Our Lord came down and walked the earth, He could easily enough have explained the whole thing to us. Yet He did not. What He did instead was to suffer. And He showed us by His own example how to deal with it. "Father, if it be possible, remove this chalice from me: yet not my will, but Thy will be done".
Now which would be easier, to explain about suffering, or to suffer oneself?
When I think of these things, I am filled with awe at the condescension of the Almighty Creator, who did these things for us.
Our Lord has spoken to more than one saint: "If there were a more perfect Way to become fit for Heaven than suffering, I would have given it to you".
And it is only the shining Catholic Faith that actually teaches us the power and value of suffering. St Catherine of Siena, in her dialogue with God, once said, "Lord, I would like to offer all my sufferings to merit the salvation of sinners". But God replied, "But Catherine, don't you realise that if you suffered as much as you possibly could, until the end of your life, it still would not be enough to make up for even one venial sin? But when you offer your sufferings in union with My Passion, I accept the love with which you do this and unite it with My Own. In this way your suffrages acquire true merit and it is then that they can be applied to sinners."
To know this is a priceless gift from God.
Suffering should not make us unhappy. It is only suffering.
"I know that my Redeemer liveth. and He shall stand on the Last Day upon the earth. And though worms destroy this body, yet in my flesh shall I see God".