18 praying always with all prayer and supplication in the Spirit, being watchful to this end with all perseverance and supplication for all the saints—
Verses 18 to 20 set forth the dynamics of prayer in spiritual warfare. It is not the armor that makes the warrior but the character of the fighter. The warrior needs to be upheld by prayer.
18 praying always
We take up our helmet and sword both by prayer and being watchful. We are to be at prayer on all occasions or every time a situation arises (1 Th 5:17). Prayer is important for spiritual conflict.
The word “all” implies concentration and thorough praying on all occasions and with every kind of prayer. There are five different kinds of prayer: confession, praise, thanksgiving, petition, and intercession.
This is the general word for prayer in the New Testament. Prayer includes all conversations with God.
and supplication [requests]
“Supplication” is a specific request of God.
in the Spirit,
Prayer must be done in the power of the Holy Spirit. The Spirit enables us to pray more adequately (Ro 8:26; Ju 20). This phrase does not mean to pray in one’s heart but to pray under the influence of the Spirit. We need His assistance in our prayer (Ro 8:26).
being watchful [alert] to this end
A good soldier keeps watch for the enemy. He never sleeps on his spiritual laurels. He is constantly on guard about praying in the Spirit.
with all perseverance
We exhibit watchfulness in prayer by our perseverance in prayer. We bring prayers doggedly to God. We give constant attention to prayer, unremitting attention (Ro 12:12). There is nothing significant we omit from prayer.
and supplication [petition]
“Supplication” is specific petition in prayer.
for all the saints—
The word “all” occurs four times in this verse. One time it is translated “always.” The Christian should not neglect to pray for all Christians.
Christians should treat prayer as something serious in their lives.
We need to pray when we are in a spiritual war. Our utmost concern in prayer should be for spiritual issues, not physical problems. We not only pray about our own spiritual problems but for the spiritual battles of others. Prayer is an act of dependence on God for whatever we might be facing.