He just got done saying in verse 24 to let that which you heard from the beginning abide and remain in you and now he says to ‘abide in Him.’  The Amplified Bible says to "abide (live, remain permanently) in Him…"

If we continue to abide in Him then when He appears—when He comes again—we will have confidence and not be ashamed before Him.  As we continue in the Word and in our relationship with Jesus Christ—the Living Word—we will not have to worry about what happens when we see Him in person.  It will be a glorious time of rejoicing and not a time of sorrow or shame.  Continue in Him and you will be extremely glad you did!

Confession:

I will continue to abide in Jesus Christ.  I will continue in my relationship with Him.  As a result, I will not be ashamed when I see Him in person.