Actually, Baptist churches do not, as a rule, have altars.
No doubt, there may be some individuals who have altars, but the purpose of an altar is to offer a sacrifice and, because we, as Christians, believe that there is no more sacrifice to be offered, we have no need for an altar.
Prophecy of an eternal sacrifice to be made and a pure offering to God, Jesus fulfilled this at the last supper and commanded the Apostles to “Do this in rememberance” this sacrifice is made on the altars of every Catholic church.
Malachi 1:11
For from the rising of the sun, even to its setting, my name is great among the nations; **And everywhere they bring sacrifice to my name, and a pure offering; For great is my name among the **nations, says the LORD of hosts.
Jesus is eternallly offering his sacrificial body and blood for all humanity before God standing in heaven (not sitting) meaning an action is taking place (the once and for all sacrifice made eternally, and made present to every age on earth through Jesus body the Holy Catholic Apostolic church’s altar in his body and blood sacrifice made by the hand of God in his Eucharist.
Revelations 5:6
Then I saw standing in the midst of the throne and the four living creatures and the elders, a Lamb 4 that seemed to have been slain. He had seven horns and seven eyes; these are the (seven) spirits of God sent out into the whole world.
Jesus confirms his priesthood in the apostles to offer up his body and blood in the Eucharist for all those who enter into the new covenant through his body and blood sacrifice. The apostles are commanded to make him present by his word to all ages until he returns finding his Catholic church doing so…
Luke 22:19
7 Then he took the bread, said the blessing, broke it, and gave it to them, saying, “This is my body, which will be given for you;** do this in memory of me.” **20
And likewise the cup after they had eaten, saying, "This cup is the new covenant in my blood, which will be shed for you.
Here Jesus consecrates the apostles and all their successors in his High Priestly Kinghood.
John 17: 7
Now they know that everything you gave me is from you,
8
because the words you gave to me I have given to them, and they accepted them and truly understood that I came from you, and they have believed that you sent me.
9
I pray for them. I do not pray for the world but for the ones you have given me, because they are yours,
10
and everything of mine is yours and everything of yours is mine, and I have been glorified in them.
11
And now I will no longer be in the world, but they are in the world, while I am coming to you. Holy Father, keep them in your name that you have given me, so that they may be one just as we are.
12
When I was with them I protected them in your name that you gave me, and I guarded them, and none of them was lost except the son of destruction, in order that the scripture might be fulfilled.
13
But now I am coming to you. I speak this in the world so that they may share my joy completely.
14
I gave them your word, and the world hated them, because they do not belong to the world any more than I belong to the world.
15
6** I do not ask that you take them out of the world but that you keep them from the evil one.
16
They do not belong to the world any more than I belong to the world.
17
Consecrate them in the truth. Your word is truth.
18
As you sent me into the world, so I sent them into the world.
19
And I consecrate myself for them, so that they also may be consecrated in truth.
20
“I pray not only for them, but also for those who will believe in me through their word, **
21
so that they may all be one, as you, Father, are in me and I in you, that they also may be in us, that the world may believe that you sent me.
22
**And I have given them the glory you gave me, so that they may be one, as we are one,
23
I in them and you in me, that they may be brought to perfection as one, that the world may know that you sent me, and that you loved them even as you loved me. **
24
Father, they are your gift to me. I wish that where I am 7 they also may be with me, that they may see my glory that you gave me, because you loved me before the foundation of the world.
25
Righteous Father, the world also does not know you, but I know you, and they know that you sent me.
26
I made known to them your name and I will make it known, 8 that the love with which you loved me may be in them and I in them.”