Are you attempting to justify hiding in the shadows, by saying that Jesus did not have a denomination, and there will be no denominations in heaven? Your straw man argument is obvious: I never claimed that Jesus belonged to a denomination or that they would exist in heaven. Your words, not mine.

The fact is that what differentiates denominations is their doctrines. And God’s Word is filled with doctrine. "I give you good doctrine, forsake ye not my law." Proverbs 4:2
The SDA denomination does not "forsake the law". We acknowledge all Ten Commandments as the definition of sin. Does yours?

"Jesus answered them, and said, My doctrine is not mine, but his that sent me.". John 7:16

The present day attacks on the Seventh Day Adventist church by other denominations are because it accepts the doctrines of the Father and the Son. Does yours?

Quit cowering behind pharisaic sophistry. I have shared my denomination. Show me the same respect, share yours. If your doctrine is so strong, so biblical, what do you have to fear from the weak, unbiblical teachings of Seventh Day Adventists?

The only "accusation" I have against you is that you do not have enough confidence in your own denomination to share it with the Seventh Day Adventists that you continually attack.

Paul and Apollos, in your misquoted verse, were both faithful Christians who accepted the Word of God. They were working for the same purpose: "I (Paul) have planted, Apollos watered; but God gave the increase." 1 Corinthians 3:6
Therefore, it was irrelevant which of them evangelized a particular person.

Replacing Paul with Ellen White and Apollos with Joseph Smith is rather disingenuous since Smith was not a Christian. They would never gave been working for the same purpose. Are you inferring that you are not a Christian?

"Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?
And what concord hath Christ with Belial? or what part hath he that believeth with an infidel?
And what agreement hath the temple of God with idols?"

2 Corinthians 6:14-16

Basically we would need more information to really comment intelligently on this matter.

Like, what is the purpose of these studies?
What has triggered the decision to have them?

For example -- in our region there have been seminars on "Muslim Theology". I have not attended any of them (yet) not sure if I will in the future. As I'm not exactly comfortable with the idea, for the Moslem religion, at it's core, is purely a "works" theology (which to a large extent is also true of the Catholic religion).

But the idea behind those lessons, is to "find ways to reach the Moslem community".
In which case, for those serious about bringing the gospel to Muslims, finding some common stepping stones to lead them to salvation in Christ, would be a helpful and useful tool.

But of course, I do not know if this is the case of the "RC theology lessons" in you original church.

Too often, in these inter-faith "lessons" the goal is to promote the idea that all religions lead to God, just respect them all and don't agitate any "right" or "wrong" -- they are all good in their own way. Yet this is a key mindset which lies at the foundation of the ecumenical program. We need to be alert to its infiltration into our thinking. Revelation makes it clear that not all "worship" leads to God.

I suppose another possible reason for those lessons could be part of preparing for the merging factor in our health institutions, that seems to be occurring -- I don't know if the school you referenced is the Adventist Health University in Florida, nor have I heard anything of it considering joining the merging trend.
However, there have been several moves elsewhere of Adventist Health systems "yoking together" with the Catholic Health systems.
There is the AMITA (a joint venture of Catholic Ascension's Alexian Brothers Health System and Adventist Midwest Health) There is the Adventist Health and the Catholic St. Joseph Health are yoking together in several western states.
That, in my view, is apostasy -- a complete reverse of the purpose for which our health institutions were founded and our health message given -- they were to be the right arm to help proclaim the three angel's message!

And this is happening in the Florida Conference???

This is happening in the Adventist churches who are picking up these ideas, from what other church members are reporting, not just Florida. It is happening in all the churches that are following the various aspects of the Willow Creek/Spiritual Formation under many names. I saw it in our church my sister helped start in Miami, the same things, but they were so subtle that I didn't recognize it. I went along till finally something allowed me to discern and become aware that it was slowly taking us away from God and His truth.