(Psalm 91: 1-2 NKJV)
"He who DWELLS in the secret place of the Most High shall ABIDE under the shadow of the Almighty."
Abiding comes by dwelling. Dwelling is done in the secret place. Jesus said the secret place was the intimate place of prayer. (Matthew 6:6)–"But you, when you pray, go into your room, and when you have shut your door, pray to your Father who is in the secret place; and your Father who sees in secret will reward you openly."
Therefore Abiding can only be done as we pray, literally “dwell in the secret place”. Without the dwelling, there is no abiding.
And the call to pray is to do so continually:
"…praying always with all prayer and supplication in the Spirit, being watchful to this end with all perseverance and supplication for all the saints"—(Eph. 6:18 NKJV)
This is the secret of Abiding and Dwelling.