One verse that is often thrown up to show me that God will not achieve his purpose of eventually restoring all to himself is Hebrews 9 : 27 which states that people are to die once, and after that to face judgement. In these people's minds judgement obviously equates to eternal torment in hell or total destruction.
Judgement is only a process - a process for deciding between right and wrong or between guilt and innocence - which then determines what the next course of action will be.
Some judgements are to free or acquit an innocent person, others are to penalise a guilty person in some way. In the latter case, the penalty is administered for the purpose of improving the guilty person's behaviour or character so that he/she will eventually be different and as free as the person who was acquitted.
So whatever the result, judgement is a good thing, not a bad thing, as all results of judgement eventually bring freedom.
Believers, who live in the Spirit, are judged daily by the Spirit. We are judged, convicted of our sin and restored to fellowship with God due to the on-going sanctifying work of the Spirit in our lives. This results in us becoming Christ-like and being made ready to rule with Him in the kingdom age.
Non-believers are judged at the Great White Throne and are purified by the lake of fire. This also results in God-likeness, but they completely miss out on ruling with Christ in the kingdom, as it is only the believers, the first-born, who have the double portion - reigning with Christ in the kingdom age and residency in the New Jerusalem.
Let's be careful we don't allow people to confuse the process (judgement) with the result of the process as a reason for not considering the eventual good outcome of every one of God's judgements.