The Fullness of God
For this cause I bow my knees (Paul’s prayer) unto the Father of our Lord Jesus Christ, Of whom the whole family in heaven and earth is named, That he would grant you, according to the riches of his glory, to be strengthened with might by his Spirit in the inner man; That Christ may dwell in your hearts by faith; that ye, being rooted and grounded in love, May be able to comprehend with all saints what is the breadth, and length, and depth, and height; And to know the love of Christ, which passeth knowledge, that ye might be filled with all the fulness of God. Ephesians 3:14-19
The Fullness of Christ
And he gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers; For the perfecting of the saints, for the work of the ministry, for the edifying of the body of Christ: Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ: Ephesians 4:11-13
The Fullness of the Holy Spirit
See then that ye walk circumspectly, not as fools, but as wise, Redeeming the time, because the days are evil. Wherefore be ye not unwise, but understanding what the will of the Lord is. And be not drunk with wine, wherein is excess; but be (being) filled with the Spirit; Ephesians 5:15-18
For in him (Jesus Christ) dwelleth all the fulness of the Godhead bodily. Colossians 2:9
Paul’s prayer: That Christ may dwell in your hearts by faith; Ephesians 3:17a. Faith is a firm persuasion or conviction brought about by hearing and hearing by the Word of God.*
Let the word of Christ dwell in you richly in all wisdom; Colossians 3:16a
Let implies submission and obedience to the word of Christ. The word of Christ is His doctrine or teaching. It is the written Word of God. Christ nearly always included it is written in His teaching and instruction. He taught with objective truth (based on fact) and not subjectively (based on feelings). Dwell is used as a verb meaning the act of providing a home or a residing place for His truth. In you describes where this residing place is. It is in our mind and heart. Richly describes in one word the quantity and the quality of His Word that we should have within us, compared to anything else within us.
It is difficult to fill a cup with one thing, when the cup is already full of something else.