1 Corinthians 1:18
For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God.
The message of the cross is powerful. It is a message of sacrificial love that this world does not know of and many do not still know about this love. God the Father Himself has this sacrificial love in Him. His only begotten Son represented this sacrificial love of the Father in Heaven to us in this sinful world, that had turned to the Devil through Adam and Eve. He sent His only Son to show that His relationship with man is love. This He had to show sacrificially. Just like a father who tries to win over his child who had strayed from him, God's love for mankind is greater. This love cannot be matched to ordinary human love. Which father on this earth would do the same thing God did through His Son. He made him the Tree of Life to give eternal life to everyone who believes, loves and obeys Him till the end. He had to sent Him to be an eternal example of obedience for all. The cross has an eternal message of obedience to the Heavenly Father. The Lord Jesus Christ learnt obedience as God's Son on earth in his human body. He was without sin and this pleased God the Father, as no man or woman as ever lived like Him on Earth to live without sin. God the Father is Holy and so this pleased Him eternally.
Hebrews 5:7-9
During the days of Jesus’ life on earth, he offered up prayers and petitions with fervent cries and tears to the one who could save him from death, and he was heard because of his reverent submission. Son though he was, he learned obedience from what he suffered and, once made perfect, he became the source of eternal salvation for all who obey him.
If the Lord Jesus Christ who is the Son of God had to learn obedience to the Father in Heaven while He was on Earth, what more us? If He had to be made perfectly a human being through his unimaginable sufferings on Earth, what more us? He was without sin even when He was tried and tested to the maximum. From His sufferings He learned obedience to the Father. What about you and me? How much we have to learn to obey all that Christ had commanded? No wonder, He commissioned His disciples to go out and make disciples by teaching them to obey everything He had commanded. We have much to learn to obey Christ our Lord. The power of the cross is the eternal and unmatched power of turning one from being disobedient to be obedient to all that Christ had commanded.
Henceforth, the power of the cross is the eternal and unmatched power of putting to death all the misdeeds of the sinful nature of the Devil in a believer of Christ. The mark of the power of the cross is obedience to Christ our Lord which will bring us to the Father in His fulness. But, how can we be full of the Father if we are not full of the Son. When the Son fills us then we will be full of the Father. But, on this Earth, how will all this be possible if God the Holy Spirit does not help us. He fills us first so that, we will be full of the Son and the Father as we fully obey Christ. God the Holy Spirit helps us by burning away the chaff of the sinful nature of the Devil in us first, before He helps to fill us with the divine nature of Christ. He is our true Helper and Counselor sent by the Father in Christ's name to us. He reminds us everything Christ had said and keeps doing that so that we fully obey Christ to have full Christformation in us. His coming into us is the guarantee of the full inheritance we have in Christ and that is, being filled with the Son and the Father. What other inheritance can we ask for while we are on earth?