Archippus was part of the church group that met in Philemon’s household (Philemon 1:2). Paul refers to Archippus as a fellow soldier (Philemon 1:2) and sends word for Archippus to take heed to the ministry that he had received in the Lord to make sure that he fulfills his mission (Colossians 4:17).

What can we learn from Archippus?
We must be fellow soldiers with other believers, supporting them in spiritual warfare, that is rampant in the heavenly places (Ephesians 6:10-18). We must make sure that the ministry (of reconciliation of man to God) that God has given to us (2 Corinthians 5:18), is not only received by us, but that it is fulfilled. The good news is that He who began the good work in you will perform it until the day of Jesus Christ (Philippians 1:6).

Colossians 4:17 (KJV)
17
And say to Archippus, Take heed to the ministry which thou hast received in the Lord, that thou fulfil it.

Philippians 1:6 (KJV)
6 Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ: