Here is Peter Kreeft's conversion story from Protestantism to a Catholicism.
He tells us that since converting, he has felt it to be his vocation to build bridges between Catholics and non-Catholics. He was also a signer to the Evangelicals and Catholic Together Statement and supports it very strongly. (I'd never heard of this stattement before. Here it is: Evangelicals & Catholics Together: The Christian Mission in the Third Millennium)
This is some of what Kreeft says on this.
"The divisions that exist now are very different than they were 50 years ago when I became a Catholic. The divisions now are far less important now, even though they still exist. That's because we face a common enemy. A culture of death. A society that is becoming increasingly anti-Christian. Whether Mary was assumed into Heaven is pretty important but what's really important is whether Jesus rose from the dead.
The common enemy that we face is doing exactly the opposite of what the devil wants us to do, namely dividing us. They are uniting us, in profound ways sometimes. Common action against a common evil like abortion has united Protestants and Catholics in their hearts and in their works even though not in their heads."
Kreeft tells of a story that he's not sure is literally true or not.
"In the early days of the pro-life movement The Catholics and southern Baptists were protesting at an abortion clinic. They went into the bubble zone and were all thrown into jail together for not observing the bubble zone. They shared a common jail cell. 24 of them. That night they didn't sleep. They prayed and sang hymns together all night. In the morning when they were released, the Baptists went home and asked their families why don’t we love Mary like the Catholics do? And the Catholics went home and asked their families if they accept Jesus Christ as their personal Savior?"
Now that's Evangelism of the trenches."