You goal is only partly achievable, since staying in one place and quiet for a prolonged period is not really a developmentally normal behavior for a 14 month old. This is not to say that the attempt will be somehow harmful, but just that the expectation of "good church behavior" at that age is not entirely realistic, no matter how many entertainments are provided.
Here are some things that have worked for me when I really needed to keep an early toddler busy and calm for a while:
Watching videos on a phone or tablet with headphones, or just with the sound off, is a common solution that is quite effective but only partly satisfactory in my opinion, since I don't love the church = cartoons time association that it's creating.
Keeping a set of quiet but highly desirable toys and books to be used ONLY during church is less fully effective but maybe more educational than just sticking them in front of a screen (babies around that age can find a way to play loudly with almost anything!) An old wallet filled with business cards, a pad of post-it notes or other 'adult' things may give you more quiet time than actual toys, depending on the child. Putting a bunch of handkerchiefs or fabric scraps into an empty tissues box is also a good one in this same vein.
Wearing the baby in a carrier and pacing at the back of the room is tiring, but may be less disruptive than some other options.