Evangelical Christians are those who genuinely believe in miracles--that God can objectively intervene in history. But while we agree that miracles have occurred, we differ greatly on whether they persist today, particularly those of healing.
There are those who see the occurrence of miracles in their lives as a proof of their faith or spirituality. Now Scripture does make a connection between people's faith and God's working miracles (Matthew 8:10, 9:22, 13:58, 14:31). But it is not quite that simple; there are cases where God works miracles when little or no faith is exhibited on the part of the recipient (John 5:1-15; Luke 7:11-17; Acts 3:1-10, 14:8-18). Scripture promises miracles in response to an imperfect faith (Matthew 17:20; Luke 17:6; Mark 9:23-25). God also refuses to grant miracles even to those whose faith is not in question (2 Corinthians 12:7-10; Matthew 26:42). Nor are miracles the result of or a proof of the spirituality of the people who work them (1 Corinthians 13:1-3; Matthew 7:21-23). Samson possessed miraculous strength, but his life was characterized by bad moral choices. While it ultimately caught up with him, it did not happen immediately (see Judges 14-16).
Also related to this is the question of whether God always heals. Jesus walks into a area full of sick people and heals one man (John 5:1-9). Paul is healing people at least to the end of the book of Acts (Acts 28:8,9), but he does not seem to have been able to heal himself (2 Corinthians 12:7-10), Epaphroditus (Philippians 2:25-27), Trophimus (2 Timothy 4:19) or Timothy (1 Timothy 5:23). Ultimately, God's working miracles always was and always is according to His will (1 John 5:14, 15; Ephesians 1:11; Matthew 26:42).
However, I also do not see any clear basis for saying miracles or certain types of miracles have passed away. (Hebrews 2:4 does not seem to me to prove this.) Also, while I do not want to deal here with the whole complex issue of spiritual gifts, I do not see a basis for saying that an individual could not have (within the Scriptural limits mentioned above) a gift or ministry in which God uses them to ask for miraculous things (1 Corinthians 12:9-10). This does not mean necessarily accepting any particular person's claim to have such a gift. It particularly does not mean accepting such unscriptural practices as charging for working miracles (Matthew 10:8) or engaging in any form of deception (1 Thessalonians 2:3).
There are undoubtedly those who, holding miracles to be a proof of faith or spirituality, may see miracles where no miracle has occurred. But it also seems to me that if faith is a factor in the miraculous, there may be those who, having dismissed miracles as irrelevant for today, may not see miracles because they are unwilling to trust God for them. This is a difficult balance to find, but I do believe the truth lies somewhere in the middle.