Jesus Christ is the past, present and future Stone.
The Bible says in Matthew 21:42...
Jesus saith unto them, Did ye never read in the scriptures, The stone which the builders rejected, the same is become the head of the corner: this is the Lord's doing, and it is marvellous in our eyes?
The PAST tense reference to Christ is: the stone which the builders rejected. The Jews rejected their Messiah.
The PRESENT tense reference to Christ is: the head of the corner. Those who've accepted Christ are placed into His body, called the Church.
You'll find the future tense reference in Matthew 21:44...
And whosoever shall fall on this stone shall be broken: but on whomsoever it shall fall, it will grind him to powder.
The FUTURE tense reference to Christ is: it shall fall, it will grind. This is a future look on nations who've neglected Christ.