Simplicity conveys a singleness of nature or unity. Therefore, its purpose is not dividable; rather, it is immutable while expressing a state of openness, frankness, or directness.
In addressing the saints in Rome, the Apostle Paul encouraged the ones with the Spiritual gift of giving to use this gift with simplicity, Romans 12:8. Whether we have the gift or not, when it comes to giving, we are not to do it under compulsion, or out from necessity, but with a cheerful heart, for the Lord loves a cheerful giver, 2 Corinthians 9:7. Therefore, let each one determine in his heart what he desires to give from his excess and do it so with simplicity, having no other intent.
In contrast to fleshly wisdom, we are to conduct ourselves in this world in simplicity and godly sincerity, 2 Corinthians 1:12. This is especially important when it comes to ones who teach the Word of God. Their purpose should always be to teach others, not to gain anything from them by teaching. An assembly should take care of its Pastor, and for those who serve well, they should provide for him a double portion; however, the intent of the Pastor should be simple, to equip them unto a work of ministry for the edification of the body of the Christ to bring them all to a unity (oneness) of the faith and a full experiential knowledge of the Son of God so that they are no longer tossed around by every wind of teaching by the trickery of men in deceit.
When it comes to someone who presents a different gospel or receives a different spirit, we are not to put up with them, for they seek to corrupt us from the simplicity that is in the Christ, 2 Corinthians 11:3. These are ones who modify the gospel to make it palatable for unbelievers, changing the grace of God into licentiousness. The gospel for salvation is clearly stated in 1 Corinthians 15:1-4, and it is the only message that has the ability to save, Romans 1:16. These false teachers among us seek to separate the saints out for themselves, teaching the traditions of men and separating the clergy from the people, which is contrary to the Christ. The Christ is referring to the new creation in which Christ is the head and the Church is the body, having no distinction between the members and the ministers, 2 Corinthians 5:17; Ephesians 1:22-23.
We are not to be those who seek to please others by our actions; rather, with simplicity of heart we are to serve as slaves of Christ, not with eye service, but doing the desirous will of God with a good mind serving the Lord, Ephesians 6:5-7. For our reward for the good we do will come from God, who does not show partiality, Colossians 3:22-25.
Just as God gives us wisdom that is singularly focused and without reproach, James 1:5, we are to use the knowledge we have in Christ to express a proper wisdom in this world while doing things with a single intent, not having a hidden agenda, but sincerity in living out who we are in Christ.