Dear children, the last hour is here. You have heard that the Antichrist is coming, and already many such antichrists have appeared. From this we know that the last hour has come. These people left our churches, but they never really belonged with us; otherwise they would have stayed with us. When they left, it proved that they did not belong with us. 1 John 2:18-19

a. The last hour means the entire church age.

Long ago God spoke many times and in many ways to our ancestors through the prophets. And now in these final days, he has spoken to us through his Son. Hebrews 1:1-2

b. Antichrist simply means "against Christ"

The man of lawlessness is revealed—the one who brings destruction. He will exalt himself and defy everything that people call god and every object of worship. 2 Thessalonians 2:3-4

It is a sign of the times we live in.

But you are not like that, for the Holy One has given you his Spirit, and all of you know the truth. So I am writing to you not because you don’t know the truth but because you know the difference between truth and lies. And who is a liar? Anyone who says that Jesus is not the Christ. Anyone who denies the Father and the Son is an antichrist. Anyone who denies the Son doesn’t have the Father, either. But anyone who acknowledges the Son has the Father also. 1 John 2:20-23

a. God’s truth

b. The anointing of the Holy Spirit.

He (God) has identified us as his own by placing the Holy Spirit in our hearts as the first installment that guarantees everything he has promised us. 2 Corinthians 1:22

Just as he (the Holy Spirit) has taught you, remain in fellowship with Christ. 1 John 2:27

So you must remain faithful to what you have been taught from the beginning. If you do, you will remain in fellowship with the Son and with the Father. And in this fellowship we enjoy the eternal life he promised us. 1 John 2:24-25 

a. Evaluate the direction of our spiritual journey.

I am writing these things to warn you about those who want to lead you astray. 1 John 2:26