Should our work only be related to Islam and God? What about those who are doctors and scientists whose work does not permit them to talk much about religion, how can their work relate to Islam?
All work is related to God because God created and sustains the cosmos.
However, certain jobs make us feel closer to God (such as useful, productive, and helpful jobs) and other jobs (such as those involving injustice, wastage, deception, etc) make us feel from God. Some jobs invite God's love and others invite God's wrath.
Medicine and the sciences inherently can lead a person towards God through consideration of the natural law of the universe and assisting humanity. Of course, in this day and age, there are many ways that they are twisted into other things (such as developing harmful food additives or biochemical weapons). So, this is really something that someone has to answer on an individual basis.
In general the believer is instructed to work for a living and work is considered an important part of worship, as long as the work is halal and healthy.
Oftentimes it is simpler not to work in the field of organized religion!