Be on your guard; stand firm in the faith; be courageous; be strong.
NMVWatch you2f, stand fast in the faith, keep on you like men (behave/act as a man should), be strong.
OJBWatch, stand firm in the emunah (faith), be men, be strong.
TCENTBe watchful, stand firm in the faith, be men of courage, and be strong.
T4TBe on guard against anything that would hinder you spiritually. You have believed the true message; continue believing it firmly. Be courageous. Keep strong in your relationship with God.