The matter of the identification with Christ is unveiled in Psalm 91.
In the identification with Christ, the saints make Jehovah the Most High their habitation, dwelling in His secret place and abiding in His shadow under His wings (vv. 1-9). We all need to dwell in God by dwelling in the secret place (v. 1). This is the real oneness with God. Here God becomes us; we are constituted with Him; and we and God live together as one.
In the identification with Christ, we are under the keeping care of the angels, and we tread upon the enemy Satan (vv. 11-13; Matt. 4:6). Psalm 91:13 says, "You will tread upon the lion and the cobra;/You will trample the young lion and the serpent." Here Satan is likened to a lion that devours God's people and to a serpent that poisons God's people. In Matthew 4 we see that while the Lord Jesus was living a human life on earth, He was under the care of the angels, who protected Him from Satan and the evil spirits. Matthew 4:11 says that angels came and ministered to Him. The angels are also protecting and safeguarding us today, as indicated by Hebrews 1.
In the identification with Christ, the saints set their love upon God; they are set on high by Him; and they see His salvation in the extension of their days (Psa. 91:14-16). These verses are a prophecy referring to Christ. Christ set His love upon God the Father. Christ has been exalted to the highest place in the heavens, and He is now seeing God's salvation in the extension of His days in resurrection. Christ died, but in resurrection He will live forever. Therefore, He could say, "I became dead, and behold, I am living forever and ever" (Rev. 1:18a). This is the extension of His days in resurrection for the carrying out of His salvation prophesied not only in Psalm 91 but also in Isaiah 53.
In all these matters we should be identified with Christ. If we are identified with Christ, we too will take God as our habitation. We will be one with Christ in His crucifixion, in His resurrection, in His ascension, and in His taking God as His habitation. Then we will live with Him and set our love upon God. Thus, we will be exalted, and we will see God's salvation in the extension of our days.