So let us seize and hold fast and retain without wavering the hope we cherish and confess and our acknowledgement of it, for He Who promised is reliable (sure) and faithful to His word.
Hebrews 10:23 (AMPC)

“That exhortation, ‘Let us hold fast,’ might well be written on the cover of every Christian’s Bible. We live in such a changeful age, that we need all to be exhorted to be rooted and grounded, confirmed and established, in the truth.”  - Charles Spurgeon

Because of what Jesus did (fulfilled the law and made a new and better covenant) and because we live in such a changeful age:

Let us

• Go right into the Presence of God with sincere hearts and fully trusting Him.
• Hold fast without wavering to the hope we affirm.
• Think of ways to motivate one another to acts of love and good works.
• Not neglect meeting together since the day of His return is drawing near.

We are being made holy; it’s a process.

For by that one offering he forever made perfect those who are being made holy.
Hebrews 10:14

Follow the “let us” instructions and encourage others to do the same.