"Blessed be the God and Father of our Lord Jesus Christ, who hath blessed us with all spiritual blessings in heavenly places in Christ." (Ephesians 1: 3)
We have been blessed with all spiritual blessings in Christ, because Christ Jesus has taken our place, dying for our sins and bringing into His status before God the Father:
"But God, who is rich in mercy, for his great love wherewith he loved us, 5Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved;) 6And hath raised us up together, and made us sit together in heavenly places in Christ Jesus:" (Ephesians 2: 4-6)
The problem for all of us, for those of us as we grow in grace and knowledge of the Lord, is that we do not walk by faith. If we do not feel or sense this new identity, then we do not believe it.
The fact remains that we cannot sense this new life, because Jesus has already died on the Cross, has already risen again, and because He lives in a redeemed body, He cannot die again.
Either we accept the record in His Word, or we do not.
So, because Christ Jesus has taken us from dead in our trespasses to alive and seated in heavenly places, we grow in grace and knowledge of all that He has done for us.
We accept that He has taken care of everything, and thus we learn to rest in His Finished Work.
"Far above all principality, and power, and might, and dominion, and every name that is named, not only in this world, but also in that which is to come: 22And hath put all things under his feet, and gave him to be the head over all things to the church, 23Which is his body, the fulness of him that filleth all in all." (Ephesians 1: 21-23)
So, Jesus Christ has blessed us with all spiritual blessings.
Therefore, let us bless Him at all times:
"I will bless the LORD at all times: his praise shall continually be in my mouth." (Psalm 34: 1)
We bless Him because He first blessed us.
Of course, John could not have written it more simply:
"We love him, because he first loved us." (1 John 4: 19)