I am new (after a long vacation)to Catholic Answers and I would like to throw in my two cents. First of all, “I form the light, and create darkness: I make peace, and create evil: I the Lord do all these things.” Isaiah 45:7 There are different “evils” that can be understood. The "evil of natural disasters and the evil of sin which is not a created thing, rather it is a turning of a free will against God’s will. God can decide what consequences follow from two “identical” sins and thereby fashion the evil that people bring upon themselves by their bad decisions. The evil of the sin God did not create, God created the free will that turned from the good and most likely said “the good ends justify the evil means”. God creates the storms and earthquakes and such as consequences of all sins so that people see, on the large and small scale, how it could be much worse and hopefully realize that if we got what we deserved for our sins, without the mercy of God, we would all be burning in hell for ever and ever and ever.
As to how can it be possible that some of us will perish? 2 Corinthians 5:19-21, “God was in Christ reconciling the world (all things) to Himself” CCC 2814, “We ask God to hallow His Name which by its own Holiness saves and makes holy all creation” and CCC 2637 " Indeed, in the work of salvation, Christ sets creation free from sin and death to consecrate it anew and make it return to the Father, for His Glory" and CCC 457, “The Word became flesh for us in order to save us by reconciling us with God.” and CCC 314, " Only at the end, when our partial knowledge ceases, when we see God “face to face” will we fully know the ways by which…"
Because of CCC 314 and a number of scripture passages we can know that we must be given truly infinite graces to see God as He is and yet we will still have free will. God cannot override our freewill. God is so infinitely good and powerful that He has created our freewill such that even when given truly infinite graces, we will still have free will, but we will not receive any merits for our freewill decision at that point. Those going to hell will also still have freewill and will freely agree with God’s Will.
God saves us by reconciling us with God. Therefore when God gives truly infinite graces to everyone at the end of time (through the Name “Jesus” spoken by Joseph and Mary in my opinion), all will be reconciled to God because each will freely choose to be reconciled with God. Those going to hell for ever and ever and ever and ever will have the peace, love, joy, thanksgiving and sorrow for sins that Jesus had on the Cross. They will also choose to not have the beatific vision and to thankfully and joyfully offer up that infinite pain of hell for the glory of God. If your God is not infinitely powerful enough to do this, just say so.