Now He who prepared us for this very purpose is God, who gave to us the Spirit as a pledge.2 Corinthians 5:5(NASB)
So much of Paul's ministry to the Church is reminding us of our eternal inheritance and our heavenly citizenship and although we have no tangible evidence of our future hope, nevertheless we accept it by faith - because God has spoken in His Word and God is faithful to His word - for God has even set His word about His holy name.
We may have no tangible proof of our home in heaven, but faith is the evidence of unseen and invisible things - and we are to govern our lives by truths that have eternal and lasting value and not to set our hearts on the passing things of this temporal world.
Paul has been contrasting our failing earthly bodies with the glorified bodies, which all who trust in Christ as Saviour will receive at His coming. Our present bodies are weak and dying. They are a temporary structures that continue to show signs of weakness and decay. But this earthen vessel will one day be glorified and the temporal will be replaced with the eternal, the mortal with the immortal and our decaying form will be dressed with a glorious body that is equipped to live with Christ - in heaven for ever.
And as a guarantee from God - all who trust in Christ Jesus as Saviour are given the indwelling Holy Spirit as a pledge - He is a guarantee from God that we will one day set aside this earthly flesh and be dressed in the heavenly glory that comes from God.
Thank You Lord that You are preparing me for my heavenly home and thank You Father that You gave the Holy Spirit as a pledge, guaranteeing my future hope in Christ - all praise to Your holy name, AMEN