The law is only a shadow of the good things that are coming – not the realities themselves. For this reason it can never, by the same sacrifices repeated endlessly year after year, make perfect those who draw near to worship.
NIV
FOR SINCE the Law has merely a rude outline (foreshadowing) of the good things to come--instead of fully expressing those things--it can never by offering the same sacrifices continually year after year make perfect those who approach [its altars].
AMP
For the law having a shadow of good things to come, and not the very image of the things, can never with those sacrifices which they offered year by year continually make the comers thereunto perfect.
KJV
They serve at a sanctuary that is a copy and shadow of what is in heaven. This is why Moses was warned when he was about to build the tabernacle: "See to it that you make everything according to the pattern shown you on the mountain."
NIV
[But these offer] service [merely] as a pattern and as a foreshadowing of [what has its true existence and reality in] the heavenly sanctuary. For when Moses was about to erect the tabernacle, he was warned by God, saying, See to it that you make it all [exactly] according to the copy (the model) which was shown to you on the mountain. [Exod. 25:40.]AMP
Who serve unto the example and shadow of heavenly things, as Moses was admonished of God when he was about to make the tabernacle: for, See, saith he, that thou make all things according to the pattern shewed to thee in the mount.
KJV