I appreciate the point you are making and linguistically the word "exercise" causes problems for some. (myself included at one time)
But having searched the Scriptures, I have reached the irrefutable conclusion that having "faith" in Christ is not enough. Acting on that faith is what merits being a Christian. As a gold ring can be tested by its hallmark, Christ stated that genuine Christians (individually or in a group) would also bear a hallmark - John 13:35.
However, the Bible gives ample evidence of what would be required of someone claiming to be a follower of Christ. Here are some examples, based on love of neighbour and Romans 10:13-15:
(Matthew 24:14) And this good news of the kingdom will be preached in all the inhabited earth for a witness to all the nations; and then the end will come.
(Matthew 28:19,20) Go therefore and make disciples of people of all the nations....teaching them to observe all the things I commanded you...
(Mark 16:15) And he said to them: "Go into all the world and preach the good news to all creation.
(Luke 9:2) And so he sent them forth to preach the kingdom of God
(1 Corinthians 9:16) If, now, I am declaring the good news, it is no reason for me to boast, for necessity is laid upon me. Really, woe is me if I did not declare the good news!
(Colossians 1:25-28)...I became a minister of this [congregation] in accordance with the stewardship from God which was given me in YOUR interest to preach the word of God fully, the sacred secret that was hidden from the past systems of things and from the past generations. But now it has been made manifest to his holy ones, to whom God has been pleased to make known what are the glorious riches of this sacred secret among the nations. It is Christ in union with YOU, the hope of [his] glory. He is the one we are publicizing, admonishing every man and teaching every man in all wisdom, that we may present every man complete in union with Christ.
(Titus 1:2-3) upon the basis of a hope of the everlasting life which God, who cannot lie, promised before times long lasting, whereas in his own due times he made his word manifest in the preaching.
(Philippians 1:15) True, some are preaching the Christ through envy and rivalry, but others also through goodwill.
(2 Timothy 4:1-2) I solemnly charge you before God and Christ Jesus, who is destined to judge the living and the dead, and by his manifestation and his kingdom, preach the word, be at it urgently in favorable season, in troublesome season, reprove, reprimand, exhort, with all long-suffering and [art of] teaching.
(Acts 20:20) while I did not hold back from telling YOU any of the things that were profitable nor from teaching YOU publicly and from house to house.
(Acts 28:30-31) . . .So he remained for an entire two years in his own hired house, and he would kindly receive all those who came in to him, preaching the kingdom of God to them and teaching the things concerning the Lord Jesus Christ with the greatest freeness of speech, without hindrance.
(Romans 10:8-15) But what does it say? "The word is near you, in your own mouth and in your own heart"; that is, the "word" of faith, which we are preaching. For if you publicly declare that ‘word in your own mouth,’ that Jesus is Lord, and exercise faith in your heart that God raised him up from the dead, you will be saved. For with the heart one exercises faith for righteousness, but with the mouth one makes public declaration for salvation. For the Scripture says: "None that rests his faith on him will be disappointed." For there is no distinction between Jew and Greek, for there is the same Lord over all, who is rich to all those calling upon him. For "everyone who calls on the name of Jehovah will be saved." However, how will they call on him in whom they have not put faith? How, in turn, will they put faith in him of whom they have not heard? How, in turn, will they hear without someone to preach? How, in turn, will they preach unless they have been sent forth? Just as it is written: "How comely are the feet of those who declare good news of good things!"
(1 Timothy 4:16) Pay constant attention to yourself and to your teaching. Stay by these things, for by doing this you will save both yourself and those who listen to you.
(1 Thessalonians 2:4) but, just as we have been proved by God as fit to be entrusted with the good news, so we speak, as pleasing, not men, but God, who makes proof of our hearts.
(1 Corinthians 9:22)...to the weak I became weak, that I might gain the weak. I have become all things to people of all sorts, that I might by all means save some.
(1 Peter 3:15)...But sanctify the Christ as Lord in YOUR hearts, always ready to make a defense before everyone that demands of YOU a reason for the hope in YOU, but doing so together with a mild temper and deep respect.
(Acts 1:8) but YOU will receive power when the holy spirit arrives upon YOU, and YOU will be witnesses of me both in Jerusalem and in all Ju·de´a and Sa·mar´i·a and to the most distant part of the earth."
(Romans 10:18) Nevertheless I ask, They did not fail to hear, did they? Why, in fact, "into all the earth their sound went out, and to the extremities of the inhabited earth their utterances."
(2 Corinthians 4:3-4) . . .If, now, the good news we declare is in fact veiled, it is veiled among those who are perishing, among whom the god of this system of things has blinded the minds of the unbelievers, that the illumination of the glorious good news about the Christ, who is the image of God, might not shine through.
(Romans 11:13) Now I speak to YOU who are people of the nations. Forasmuch as I am, in reality, an apostle to the nations, I glorify my ministry,
(Revelation 14:6) And I saw another angel flying in mid heaven, and he had everlasting good news to declare as glad tidings to those who dwell on the earth, and to every nation and tribe and tongue and people,
(Romans 1:15-16) so there is eagerness on my part to declare the good news also to YOU there in Rome. For I am not ashamed of the good news; it is, in fact, God’s power for salvation to everyone having faith, to the Jew first and also to the Greek;
(1 Corinthians 9:16) If, now, I am declaring the good news, it is no reason for me to boast, for necessity is laid upon me. Really, woe is me if I did not declare the good news!
(Acts 20:24) Nevertheless, I do not make my soul of any account as dear to me, if only I may finish my course and the ministry that I received of the Lord Jesus, to bear thorough witness to the good news of the undeserved kindness of God.
Takes great faith, courage, and knowledge to talk to others about your faith in Christ's ransom - but clearly, someone's got to do it!