Hymns books vary more than we had anticipated and the slight changes in words can take you by surprise if you don't check the wording of hymns before the day. Growing up I remember learning new hymns at choir practice and then we taught the congregation the tunes once we had mastered them.
Another popular hymn that I hear frequently is 'I The Lord of sea and sky' or alternatively known as 'Here I am Lord'. This is often sung at many funeral services, I think because not only is it a catchy easy tune to sing, the words do give hope and comfort in times if grief.
More recently I had to learn a new hymn 'On eagle's wings'. This is not necessarily an easy hymn to learn, as each verse differs slightly and not the way you expect, but once mastered it is a lovely joyful hymn to make your heart soar.
Of course as a musician having the music to read and play makes it a lot easier to learn than if you don't read music. So, how do you do it if that applies to you? We'll, to be honest You Tube is an amazing resource, you would be surprised how many renditions of new and traditional hymns can be found there. I must admit that when a hymn new to me is requested, I'll often head for You Tube, as I can hear various versions in different keys, with different choirs or soloists so can get a good idea of how easy it is for people to sing.
I now am on the lookout for a new hymn to learn, and I'll post it here when I've found just the right one.