When we think about the self-exalting reasons why Simon wanted to be in the church in Acts 8 and then also reasons why people are attracted to the church in our day, it becomes clear that involving oneself in the movement called Christianity has the potential to be the greatest idolatry one can engage in since many come for self-serving reasons which defame Christ.
For that reason, it’s true that the most detrimental and unloving thing that could happen is that we allow Simons to remain attached to the church without a direct call for repentance. To simply be happy that Simons desire to be involved in Christianity is unloving for the Simons AND for the church, and therefore despicable in God’s sight. If we want to glorify God and be used by Him, then we must love Simons by calling them to repentance and we must love the bride of Christ by keeping ourselves holy (1 Pet. 2:9), by denying worldly lusts (Titus 2:11ff) and by seeking to be filled with the fullness of God’s character (Eph. 1:23;3:19).
The good news is that, when the gospel is truly preached and lived out, there is no opportunity for Simons to have this kind of self-centered attachment to the church, at least on a long-term basis.