1 Thessalonians 4.1 describes how you must live and please God.
There is an expectation that God has about us after we have asked His forgiveness for our disobedience and have now committed ourselves to following Him.
God’s expectation is that we would live in such a way that His character and will would be clearly seen through our words and deeds and that the focus of our lives would be the Kingdom of God coming to earth as it is in heaven. God expects His people to live like Him and to join Him in His work of restoring the world to Himself in Jesus Christ.
Paul defines living like God in this text as being holy and avoiding sexual immorality. Holiness is an obscure word to our modern ears but it means literally set apart for God’s use or in the case of God Himself, set apart as pure and undefiled, perfect in every way.
So too the people of God are no longer pursuing worldly ways like titles and treasures or various pleasures but instead are living examples of the life of Jesus who are thoroughly engaged in the work of God which is the seeking and saving of the lost.
Jesus is not our Savior simply to keep us from the wrath of God to come but He is our Lord Who engages us now for serving today His purposes which is all people everywhere coming to know Him personally and living like Him always.
This is what it means to call ourselves Christian; it goes far beyond belief in God and weekly attendance at Church.
Christianity is seeking God, obeying His commands while engaging His work for His glory both now and forevermore.