Your prayer from Ephesians chapter 3 verses 14 through 20 is one of the deepest prayers in Scripture, and it is beautiful that you are asking God to make it real in your own life. To be strengthened with power through His Spirit in the inner person, to have Christ dwell in your heart through faith, to be rooted and grounded in love and to know the love of Christ that passes knowledge, and to be filled with all the fullness of God is exactly what the Father wants to do for His children.
That strengthening is not something you can work up on your own. Before coming to Jesus your spirit was dead, and the world does not know this kind of love. It is only as God makes your spirit alive and puts His Spirit within you that you can know it. Scripture says we know that we dwell in Him and He in us because He has given us His Spirit, and the clear evidence of His Spirit dwelling in you is not an outward or dramatic display. Counterfeits exist for many outward things, but the true fruit of the Spirit is love. God is love, and when His Spirit is in you, His love will be manifested in you, especially in a growing love for Him and for His people.
That is also how you can have assurance that Christ is dwelling in your heart through faith. Every spirit that confesses that Jesus the Messiah has come in the flesh is of God. Your faith confesses Jesus Christ as Lord and Savior who came in the flesh, died and rose again, and that confession itself is a witness that you belong to Him. If the Spirit of Christ dwells in you, you are His. You are no longer in the flesh but in the Spirit, and there is therefore now no condemnation for you who are in Christ Jesus and who seek to walk after the Spirit. God has written a new law, the law of the Spirit of life in Christ Jesus, on your heart. He sees your love for Him and your desire to please Him even while He is still at work in you. There are still areas under construction, but He is faithful to complete what He has begun.
To be rooted and grounded in love and to comprehend the width and length and depth and height of Christ's love is to enter into something that goes beyond natural understanding. This is not human affection. It is agape, the self giving love of God that was shown when Christ humbled Himself and became obedient even to death on the cross for you. It is love in the realm of the spirit, and you cannot manufacture it or develop it by trying harder. It comes only as you walk in the Spirit and are led by the Spirit. As you do, that one fruit of the Spirit, love, begins to show itself as joy, peace, patience, kindness, goodness, faithfulness, gentleness and self control. All of those are simply descriptions of what love looks like in daily life. This love is superior to any spiritual gift or any sacrifice, because gifts will pass away and sacrifices profit nothing without love, but love abides forever. It is the greatest because it endures.
Here is how love is made perfect in you, by dwelling in God and God dwelling in you. As you stay in close communion with Him, His Spirit bears witness with your spirit that you are His child and His heir. Nothing can separate you from that love. Not tribulation or distress or persecution or any other hardship. The same power that works in you to will and to do His good pleasure is the power that is able to do exceedingly abundantly above all that you ask or think.
So continue to bow your knee to the Father and ask Him for this. Ask to be controlled by His Spirit, to walk in love, to reckon the old nature dead with Christ and to live in newness of life. Ask Him to open your heart more and more to the unsearchable riches that are yours in Christ, and to let the love of Christ constrain and motivate all that you do. He will answer, and to Him be glory in your life as Christ is formed more fully in you.