By your patience possess your souls

Luke 21:19
By your patience possess your souls.

There is a distinction that we are spirit beings who live in a physical body and we possess a soul. The soul is the intellect, the mind, the emotions and feelings. The trouble is that these intellect, mind/thinking, emotions and feelings often takes first priority in us because we regard them as the truth. However they can be mistaken in thinking, emotions and so on. We know of a greater spiritual truth in Yshua and His revealed Word. Better that we take hold of the Word and let the Holy Spirit guide us. We can then use our intellect to check if things are consistent with the Word. Then developing patience, we can also put our emotions in check.

You will keep him in perfect peace

Isaiah 26:3
You will keep him in perfect peace,
Whose mind is stayed on You,
Because he trusts in You.

Our minds are incredibly complex - served in most part by the amazing organ called the brain. It is more than just the physical brain - the mind has a connection to our spirit, and is regarded as the source of our soul. Everyday the mind can entertain an infinite variety of thoughts. God has one advice for us, and that is to keep our minds focussed on Him.

Firstly we need to trust God to keep our minds on Him. Secondly we must will it to make our minds focussed on God. Thirdly the rewards for keeping our minds on God is perfect peace. This would be the peace described as "surpassing understanding". When we go through trouble it is worthwhile to think of God and remember His promises. When we are successful or going through blessed moment, we still need to keep our minds on God lest we fall far down.