As with many words in our English translations the word satan has a different or broader meaning than what is taught. Our English translations are responsible for many doctrines that may not have been intended. So here is a very short, incomplete, look at the words satan and devil. Here are the definitions for satan and devil from the Hebrew and Greek. According to Mr Strong the first word in the definitions is the most accurate meaning with anything after that becoming more unreliable.
Satan
Old Testament
H7854 satan, from H7853; an opponent or adversary; especially (with the article prefixed) Satan, the arch enemy of good. Noun.
New Testament G4567 satanas, Of Chaldee origin corresponding to G4566 (with the definite article affixed); adversary, the accuser, that is, the devil. Noun. (From Babylon)
Devil New Testament (devil is not found in the old testament) G12228 diabolos, From G1225; a traducer; specifically Satan (compare [H7854-satan]) Adjective, prone to slander, slanderous, accusing falsely
These are general use words and do not necessarily invoke the idea of a super natural entity. Notice that the word devil is not a noun, but rather an adjective. It is a description.
Through out the old testament there is never any mention of a "Satan" until the later years of King David's reign. By the way, there is also no verse explaining that the serpent in the garden is a satan or devil. Let's take a look at the first instance of the word satan found in scripture. The verse is in 1 Chronicles 21:1.
1 Chronicles 21:1
And Satan stood up against Israel, and provoked David to number Israel.
So who is this Satan, this opponent, who just shows up one day to provoke David to sin by numbering Israel? Scripture does not make us guess.
2 Samuel 24:1
And again the anger of Yahweh was kindled against Israel, and he moved David against them to say, Go, number Israel and Judah.
2 Samuel not only tells us who the opponent or adversary of Israel was, but why he was an opponent. Israel sinned and God provoked David to number the people. Joab knowing that numbering the people was wrong tried to talk David out of it. God used this to punish Israel.
So there are quite a number of verses that mention devil in the new testament.
Mark 4:11 Then the devil leaveth him, and, behold, angels came and ministered unto him.
Remember that the word devil is an adjective and not a noun. It might have been a bit more accurate to translate the verse as follows.
Then a false accuser leaveth him, and, behold, angels came and ministered unto him.
Now the interpretation can be a "Satan", "Devil" or who ever the context indicates. It is best if scripture tells us what it means and not what man thinks. Consider this as you read further in scripture. Sometimes we like to blame someone else when the problem is us.
Jeremiah 17:9 The heart is deceitful above all things, and desperately wicked: who can know it?
James 1:14 But every man is tempted, when he is drawn away of his own lust, and enticed.