These two religions are quite different. Evangelicalism is basically the Baptist Faith with all of its short-comings. Baptistic theology is essentially Marcionism with a splash of pietism for flavour. It is deeply Marcionite because it rejects the Old Testament as just a collection of prophecies about Christ, feeling that that is about all it is there for. It has no understanding of the Abrahamic Covenant at all, and cannot see that it is the Ur-covenant that the Lord Jesus came to fulfil. This Ur-covenant is entirely invisible to them, even when you point it out. You may point to the Magnificat where Mary speaking by the Holy Spirit prophecies that God has remembered the covenant that he swore to our father Abraham, but it will make no difference. You will be told that there is continuity and discontinuity between the new and the old, but you will not be told exactly what that means, probably because they do not know. This response is a standard reply, and it serves as a catch-all cliche to cover just about anything.
There is of course the overwhelming acceptance of Darwinist thinking as well that makes the history of the Bible effectively irrelevant. The six day creation event is rejected as a metaphor for Darwinism, as is everything in the first eleven chapters of Genesis. What use is there for an allegedly flawed book such as Genesis?
This double whammy of Marcionite exclusive New Testamentism and Darwinism makes the majority of the biblical texts utterly irrelevant to evangelicals.
In stark contrast the Reformed Faith is founded upon the WHOLE Bible. The whole Bible is inspired and recorded history, and it is ALL useful for teaching etcetera. The New Testament is the fulfilment of the promises that God swore on oath to Abraham, and it is this single insight that binds the old to the new in indissoluble bonds.
What is new is that Moses has been cancelled. This is exactly what the OT said would happen when the New Covenant was made with Israel. Moses was always an interim arrangement until Christ should appear to fulfil Abraham and to redeem Israel.
The evangelical idea of the church is deeply flawed because they cannot seer that it is Israel simpliciter. The church is not a new Israel, or a replacement Israel, it is the old Israel with one subtle difference – it has newly ingrafted branches of the Gentiles. These new branches do not make a new tree, they make new branches. These grafts are implanted into the old Israel Tree according to Paul, so that we are now co-heirs with the Jews in – wait for it – the commonwealth of Israel!
This is, of course, covenant theology, plain and simple, and it is these insights that put clear water between the Reformed Faith and evangelicalism, and indeed, all other forms of Christianity.