Now He who establishes us with you in Christ and has anointed us is God, who also has sealed us and given us the Spirit in our hearts as a guarantee.
2 Corinthians 1:21-22 (NKJV)
It is crucial that we have a correct understanding of the doctrine of the Trinity since it explains the nature and character of God. When we understand who God is and what He is like and how He works, then we are able to love Him more faithfully and partner with Him more fruitfully.
The Apostle Paul tells us how our salvation is both the will and works of the three Persons of the Trinity. It is through the death and resurrection of His Son Jesus that the Father God has reconciled the world to Himself (cf. 2 Corinthians 5:18-19) and we have the witness of the Spirit in us to assure us of eternal life and make us willing to believe and follow after Christ.
What God is doing for us right now, He is doing in the light of what He has already done for us in Christ. We are chosen and accepted in the Beloved. God is completely pleased and satisfied with what Jesus has accomplished for us on the cross and we experience His accomplishment through the presence and power of the Holy Spirit within us.
God had given us His Holy Spirit to enable us to will and work for His pleasure.
We don't have to work hard to please God since He is already pleased with us because He is delighted with His Son, in whom we have "become the righteousness of God" (2 Corinthians 5:21). Everything we do is not so much about pleasing God as it is about responding to His grace at work in and through us.
When we respond to the Spirit by believing the truth of who we are and what we have in Christ, we will enjoy and glorify our Father now and forever. We live confidently and pray gratefully because we know we belong and share the fullness of life and love of the Trinity.