Matthew 5:18 For assuredly, I say to you, till heaven and earth pass away, one jot or one tittle will by no means pass from the law till all is fulfilled.
What does this verse mean?
The “jot” is the smallest of the Hebrew letters. The “tittle” is a little decorative mark or point on the “jot”. The phrase is the English equivalent of “crossing every ‘T’ and dotting every ‘I'”.
Jesus was NOT saying that Christians are obligated to KEEP the law and regulations of Moses. If this were true, we could not pick and choose what suited us (like keeping the Sabbath); we would be bound to all the Law (dietary laws, sacrificing, etc.)
You can’t have it both ways, as some try today.
What Jesus was saying that the effect of the Law to convict of us sin, to rightly condemn us for unholiness and to be God’s measurement of righteousness would not pass away until “all is fulfilled”.
When will “all be fulfilled”? When the entire plan of God for mankind is fulfilled, when the final judgment is done, when those who reject God are cast into everlasting darkness, and those washed by the blood of the Lamb are home forever with their Savior.
With that time comes, all will be fulfilled, and there will be no need for the Law anymore.
Until then, not one letter or word will pass away, but will remain in effect to convict men of sin and direct people to Christ.