A testimony is spiritual knowledge of truth obtained by the power of the Holy Ghost. Continuing conversion is constant devotion to the revealed truth we have received—with a heart that is willing and for righteous reasons. Knowing that the gospel is true is the essence of a testimony. Consistently being true to the gospel is the essence of conversion. We should know the gospel is true and be true to the gospel.
Elder David A. Bednar, "Converted unto the Lord", General Conference, October 2012
Elder Bednar talks about the ten virgins and their lamps in his discourse. He calls them the lamps of testimony and the oil of conversion. Notice that all ten virgins in this story have lamps, or, in other words, they all have testimonies.
Only half of these ten have the oil of conversion in their lamps, and it's filled full.
We know that half of all members of the Church will fall away or neglect to do what's required. Using Elder Bednar's insight into this parable means that of all the members that are portrayed in this parable, have a testimony. But...only half of them will make it.
This is completely different insight and understanding than what I've learned over the years from this parable. This new insight may be common knowledge to others, but I've always understood this to mean that half of the members do not or will not even have a testimony, and, therefore, won't make it. Afterall, Matthew 13:38 teaches us that the tares are children of the wicked one. Are those with testimonies children of the wicked one? I've always thought those were the wheat. I've understood that as long as I have a testimony, I should be okay.
But....this makes sense to me. Makes more sense to me actually. I understand that the Lord is sifting the wheat from the tares. We know that. But, now consider that the wheat all have testimonies (as I understand it), but only half of them will reach exaltation. That means 25% of every child of God. Of course, this is just my thinking, not actual doctrine.
When the Bridegroom comes, having a testimony alone will not be sufficient to be invited in. It's "daily" devotion to that testimony and the truths we have learned, that will get us invited in.