I have persistent and chronic lower back pain and have had x-rays done. would an mri help find spinal issues?

Yes and no: There is no doubt that an MRI is much more sensative in determining the cause of back pain than a plain X-ray alone; predominantly because an MRI shows soft tissues such as discs, nerves, and muscles while an X-ray does not. But because an MRI is extremely sensative, one needs to be careful in that there are a log of "abnormal" findings on an MRI that might be a symptomatic.