Romans Chapter 7 Vs. 3

Released from the Law

So then if, while her husband liveth, she be married to another man, she shall be called an adulteress: but if her husband be dead, she is free from that law; so that she is no adulteress, though she be married to another man. Rom 7:3

but if her... The law that governs a married woman’s actions no longer has any jurisdiction over her once her husband dies. Widows are free to marry again, and Paul even encourages younger ones to remarry, as long as their potential mate is a believer. (1Cor. 7 3:9 and 1Tim. 5:14).

Here again, we see that husbands and wives are one flesh until one is taken in death. The obligation is to the flesh (not the spirit).

Then Paul continued the illustration, pointing out that if a wife marries (lit., “if she comes to”) another man while her husband is still alive she is called (future tense, “shall be publicly known as”) an adulteress. Conversely, on the death of her husband she is free from that marriage (cf. Rom. 7:2). So she is not an adulteress if she marries (lit., “even though she comes to”) another man. A widow who marries again is not guilty of adultery.